Transistor: Wikis

  
  

Encyclopedia

From Wikipedia, the free encyclopedia

.
Assorted discrete transistors.
^ Assorted discrete transistors An Electronic Component made by joining semi-conductor of P-Typed and N-Typed in the following configuarations .
  • Transistor – Wikibooks tiếng Việt 15 January 2010 9:09 UTC vi.wikibooks.org [Source type: Academic]

Packages in order from top to bottom: TO-3, TO-126, TO-92, SOT-23
.A transistor is a semiconductor device used to amplify and switch electronic signals.^ A transistor is an electronic control device, where an electrical signal input can control another electrical signal.
  • Digital Circuits/Transistor Basics - Wikibooks, collection of open-content textbooks 15 January 2010 9:09 UTC en.wikibooks.org [Source type: FILTERED WITH BAYES]

^ TUBES TO TRANSISTORS Transistors are solid-state devices used to amplify or switch electronic signals.

^ Using a transistor as a switch .
  • Transistor Circuits 15 January 2010 9:09 UTC www.kpsec.freeuk.com [Source type: FILTERED WITH BAYES]

.It is made of a solid piece of semiconductor material, with at least three terminals for connection to an external circuit.^ A transistor is made of a solid piece of a semiconductor material ...
  • transistor - Search Results - MSN Encarta 19 September 2009 23:26 UTC encarta.msn.com [Source type: General]
  • Transistor - ninemsn Encarta 19 September 2009 23:26 UTC au.encarta.msn.com [Source type: Academic]
  • Transistor - MSN Encarta 19 September 2009 23:26 UTC uk.encarta.msn.com [Source type: FILTERED WITH BAYES]
  • Transistor - MSN Encarta 19 September 2009 23:26 UTC ca.encarta.msn.com [Source type: Reference]

^ Transistors are typically designed with at least three terminals, one of which (the base) serves as a sort of control gate (for lack of a better term).
  • Glossary: Transistor | Sweetwater.com 15 January 2010 9:09 UTC www.sweetwater.com [Source type: FILTERED WITH BAYES]

^ Capable of performing many functions of the vacuum tube in electronic circuits, the transistor is a solid-state device consisting of a tiny piece of semiconductor , usually germanium or silicon , to which three or more electrical connections are made.
  • Transistor - ninemsn Encarta 19 September 2009 23:26 UTC au.encarta.msn.com [Source type: Academic]
  • Transistor - MSN Encarta 19 September 2009 23:26 UTC uk.encarta.msn.com [Source type: FILTERED WITH BAYES]

.A voltage or current applied to one pair of the transistor's terminals changes the current flowing through another pair of terminals.^ A small current flows through the base of the transistor.
  • How It Works: Reed Switch Motor with Transistor 15 January 2010 9:09 UTC www.simplemotor.com [Source type: FILTERED WITH BAYES]

^ A PNP transistor is not on until current is applied.
  • Make: Online : MAKE presents: The Transistor 15 January 2010 9:09 UTC blog.makezine.com [Source type: FILTERED WITH BAYES]

^ A voltage applied to the junction controls a current flowing through the other two terminals.
  • Transistor - BEAM Robotics Wiki 15 January 2010 9:09 UTC www.beam-wiki.org [Source type: Reference]

.Because the controlled (output) power can be much more than the controlling (input) power, the transistor provides amplification of a signal.^ A transistor is an electronic control device, where an electrical signal input can control another electrical signal.
  • Digital Circuits/Transistor Basics - Wikibooks, collection of open-content textbooks 15 January 2010 9:09 UTC en.wikibooks.org [Source type: FILTERED WITH BAYES]

^ This is much more efficient in terms of power.
  • So I acquired this pair of vintage Yamaha M-45 Class A stereo amplifiers this afternoon... - Straight Dope Message Board 15 January 2010 9:09 UTC boards.straightdope.com [Source type: FILTERED WITH BAYES]

^ A transistor controls a large electrical output signal with changes to a small input signal.
  • What is a Transistor - Electronics 15 January 2010 9:09 UTC www.reuk.co.uk [Source type: FILTERED WITH BAYES]

.Some transistors are packaged individually but many more are found embedded in integrated circuits.^ An integrated circuit version will have many transistors and a few resistors.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Some transistors are packaged individually but most are found in integrated circuits.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ They are generally packaged in integrated circuits.
  • Transistors, Transistors Manufacturers, Transistors Suppliers, Transistors Wholesale 15 January 2010 9:09 UTC www.digitivity.com [Source type: News]

.The transistor is the fundamental building block of modern electronic devices, and its presence is ubiquitous in modern electronic systems.^ A transistor is a semiconductor device used to amplify or switch electronic signals, and it is the fundamental building block of modern electronic devices.
  • World's first molecular transistor created .:. newkerala.com Online News -29679 15 January 2010 9:09 UTC www.newkerala.com [Source type: News]
  • World's first molecular transistor created 15 January 2010 9:09 UTC news.webindia123.com [Source type: News]

^ The transistor is the fundamental building block of computers, and all other modern electronic devices.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ Although transistors, which amplify or switch electric signals, are the fundamental building blocks of modern electronic devices, this molecular model is more of a scientific discovery than a technological breakthrough for now.
  • First molecular transistor created - Discovery.com- msnbc.com 15 January 2010 9:09 UTC www.msnbc.msn.com [Source type: News]
  • First Molecular Transistor Created : Discovery News 15 January 2010 9:09 UTC news.discovery.com [Source type: General]

Contents

History

A replica of the first working transistor.
.Physicist Julius Edgar Lilienfeld filed the first patent for a transistor in Canada in 1925, describing a device similar to a Field Effect Transistor or "FET".[1] However, Lilienfeld did not publish any research articles about his devices,[citation needed] nor did his patent cite any examples of devices actually constructed.^ Field effect transistors are high impedance devices.
  • transistor@Everything2.com 15 January 2010 9:09 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ MOS-type transistors - Field-effect transistors .
  • transistor (electronics) -- Britannica Online Encyclopedia 15 January 2010 9:09 UTC www.britannica.com [Source type: Reference]

^ The first patent for the field-effect transistor principle was filed in Canada by Austrian-Hungarian physicist Julius Edgar Lilienfeld on October 22, 1925, but Lilienfeld did not publish any research articles about his devices, and they were ignored by industry.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

.In 1934, German inventor Oskar Heil patented a similar device.^ Another development came in 1934, when physicist Oskar Heil patented another type of field-effect transistor.

^ In 1934 German physicist Dr. Oskar Heil patented another field-effect transistor.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

[2]
.In 1947, John Bardeen and Walter Brattain at AT&T's Bell Labs in the United States observed that when electrical contacts were applied to a crystal of germanium, the output power was larger than the input.^ The transistor was invented at Bell Labs in 1947 by John Bardeen, Walter Brattain and William Shockley.
  • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

^ Bell Labs by William Shockley and his research team of John Bardeen and Walter Brittain.

^ IN DECEMBER 1947, Bells Labs scientists John Bardeen and Walter Brattain first revealed what would come to be known as the transistor.
  • The transistor at 60 - Technology - smh.com.au 15 January 2010 9:09 UTC www.smh.com.au [Source type: News]

.Solid State Physics Group leader William Shockley saw the potential in this, and over the next few months worked to greatly expand the knowledge of semiconductors, and thus could be described as the "father of the transistor". The term was coined by John R. Pierce.^ J.R. Pierce, Bell Labs engineer who coined the term 'transistor' .
  • Bell System Memorial- Bell Labs History of The (the "crystal Triode") 15 January 2010 9:09 UTC www.porticus.org [Source type: General]

^ It is the solid-state analog to the triode electron tube ; the transistor has replaced the electron tube for virtually all common applications.
  • transistor Facts, information, pictures | Encyclopedia.com articles about transistor 15 January 2010 9:09 UTC www.encyclopedia.com [Source type: FILTERED WITH BAYES]

^ Comments 0 0 1 0 Hey Jeff , thanks for reminding me that on December 16th, 1947 William Shockley, John Bardeen & Walter Brattain created the first working transistor , the basic building block that helped build some nations and a few trillion dollar fortunes.
  • Hey Transistor, Happy 60th. Now Move Closer – GigaOM 15 January 2010 9:09 UTC gigaom.com [Source type: General]

[3] .According to physicist/historian Robert Arns, legal papers from the Bell Labs patent show that William Shockley and Gerald Pearson had built operational versions from Lilienfeld's patents, yet they never referenced this work in any of their later research papers or historical articles.^ Bell Labs by William Shockley and his research team of John Bardeen and Walter Brittain.

^ J unction transistor theory developed by William Shockley at Bell Labs.
  • Transistor Museum Historic Semiconductor Timeline Index 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: Reference]

^ Legal papers from the Bell Labs patent show that Shockley and Pearson had built operational versions from Lilienfeld’s patents, yet they never referenced this work in any of their later research papers or historical articles.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

[4]
.The first silicon transistor was produced by Texas Instruments in 1954.[5] This was the work of Gordon Teal, an expert in growing crystals of high purity, who had previously worked at Bell Labs.^ Gordon Teal at Texas Instruments (TI) directed the development of the silicon transistor.
  • Bell System Memorial- Bell Labs History of The (the "crystal Triode") 15 January 2010 9:09 UTC www.porticus.org [Source type: General]

^ First Transistor In 1954, TI pioneered the commercialization of the silicon transistor.
  • Transistor Definition from PC Magazine Encyclopedia 15 January 2010 9:09 UTC www.pcmag.com [Source type: General]

^ Texas Instruments was the primary manufacturer of silicon transistors in the 1950s.
  • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

[6] The first MOS transistor actually built was by Kahng and Atalla at Bell Labs in 1960.[7]

Importance

.The transistor is the key active component in practically all modern electronics, and is considered by many to be one of the greatest inventions of the twentieth century.^ Importance == The transistor is considered by many to be the greatest invention of the twentieth century.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ Almost all modern electronic equipment makes use of transistors.

^ The transistor is acknowledged today as one of the greatest inventions in history.

[8] .Its importance in today's society rests on its ability to be mass produced using a highly automated process (semiconductor device fabrication) that achieves astonishingly low per-transistor costs.^ Highly automated manufacturing processes, resulting in low per-unit cost.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ Its importance in today’s society rests on its ability to be mass produced using a highly automated process (fabrication) that achieves astonishingly low per-transistor costs.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ I. Introduction Complementary Metal-Oxide Semiconductors (CMOS) logic devices are the most common devices used today in the high density, large number transistor count circuits found in everything from complex microprocessor integrated circuits to signal processing and communication circuits.
  • Transistor Level Implementation of CMOS Combinational Logic Circuits 15 January 2010 9:09 UTC et.nmsu.edu [Source type: Reference]

.Although several companies each produce over a billion individually-packaged (known as discrete) transistors every year,[9] the vast majority of transistors now produced are in integrated circuits (often shortened to IC, microchips or simply chips), along with diodes, resistors, capacitors and other electronic components, to produce complete electronic circuits.^ Discover new Power Transistor and other Electronic Components ...

^ Discover new Power transistors/transistor modules and other Electronic Components ...
  • Power transistor/transistor module Manufacturers & Suppliers 15 January 2010 9:09 UTC www.globalsources.com [Source type: General]

^ Some transistors are packaged individually but most are found in integrated circuits.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

.A logic gate consists of up to about twenty transistors whereas an advanced microprocessor, as of 2006, can use as many as 1.7 billion transistors (MOSFETs).^ Pass Transistor and transmission gate logics .
  • transistor logic ebook Download 15 January 2010 9:09 UTC www.toodoc.com [Source type: FILTERED WITH BAYES]

^ In addition, this logic family uses lower voltages, less power, and operates at higher speeds, since only small currents are needed to turn on the transistors.
  • Bipolar Transistor Logic 15 January 2010 9:09 UTC www.cs.utah.edu [Source type: Reference]

^ Generally a Transistor is build up of two electrodes, a source and a sink, along with a gate to cont … more → .
  • Transistor — Blogs, Pictures, and more on WordPress 15 January 2010 9:09 UTC en.wordpress.com [Source type: General]

[10] ."About 60 million transistors were built this year [2002] ...^ Top and side view of functioning pnumatic transistor built from lucite Get a million of these and you will have a pneumatic Pentium!
  • Pnuematic CMOS Lecture 15 January 2010 9:09 UTC www.mine-control.com [Source type: Original source]

^ Page 2: The transistor: 60 years old and still switching Page 3: The transistor: 60 years old and still switching .
  • EETimes.com - The transistor: 60 years old and still switching 15 January 2010 9:09 UTC www.eetimes.com [Source type: News]

^ About 60 million transistors were built this year [2002] ...
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

for [each] man, woman, and child on Earth."[11]
.The transistor's low cost, flexibility, and reliability have made it a ubiquitous device.^ The transistor’s low cost, flexibility and reliability have made it a universal device for non-mechanical tasks, such as digital computing.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ Its small size, low heat generation, high reliability, and low power consumption made possible a breakthrough in the miniaturization of complex circuitry.
  • transistor (electronics) -- Britannica Online Encyclopedia 15 January 2010 9:09 UTC www.britannica.com [Source type: Reference]

^ They are extensively exported to our clients worldwide for the reason that they are inexpensive, flexible and reliable which has made it a ubiquitous device.

.Transistorized mechatronic circuits have replaced electromechanical devices in controlling appliances and machinery.^ Transistorized mechatronics circuits have replaced electromechanical devices for the control of appliances and machinery as well.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ Advantages === The key advantages that have allowed transistors to replace their vacuum tube predecessors in most applications are: * Small size and minimal weight, allowing the development of miniaturized electronic devices.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ Over the next two decades, transistors gradually replaced the earlier vacuum tubes in most applications and later made possible many new devices such as integrated circuits and personal computers.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

.It is often easier and cheaper to use a standard microcontroller and write a computer program to carry out a control function than to design an equivalent mechanical control function.^ It is often easier and cheaper to use a standard microcontroller and write a computer program to carry out a control function than to design an equivalent mechanical control function.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ Apparently, as it turns out, many of the same manufacturing and design ideas that people have been applying to computer systems and microprocessor technology matter in the world of solar.
  • transistor Resources | ZDNet 15 January 2010 9:09 UTC updates.zdnet.com [Source type: General]

^ Or the load such as a DC Motor may need to have its speed controlled using a series of pulses (Pulse Width Modulation) and transistor switches will allow us to do this faster and more easily than with conventional mechanical switches.

Usage

.The bipolar junction transistor, or BJT, was the most commonly used transistor in the 1960s and 70s.^ The most common type of transistor is a bipolar junction transistor .
  • What is a Transistor - Electronics 15 January 2010 9:09 UTC www.reuk.co.uk [Source type: FILTERED WITH BAYES]

^ Bipolar Junction Transistor (BJT) Bipolar transistors, having 2 junctions, are 3 terminal semiconductor devices.

^ A basic introduction to bipolar junction transistors .
  • What is a Transistor - Electronics 15 January 2010 9:09 UTC www.reuk.co.uk [Source type: FILTERED WITH BAYES]

.Even after MOSFETs became widely available, the BJT remained the transistor of choice for many analog circuits such as simple amplifiers because of their greater linearity and ease of manufacture.^ Transistors & Mosfets We offer a wide range of transistors and MOSFET transistor for both digital and analog circuits.

^ Circuit diagram for an amplifier using an n-p-n transistor.
  • n-p-n transistor (electronics) -- Britannica Online Encyclopedia 15 January 2010 9:09 UTC www.britannica.com [Source type: Reference]

^ Transistor Amplifier - A simple two-stage Amplifier.
  • Transistor Electronic Circuits, page 1 15 January 2010 9:09 UTC www.discovercircuits.com [Source type: FILTERED WITH BAYES]

.Desirable properties of MOSFETs, such as their utility in low-power devices, usually in the CMOS configuration, allowed them to capture nearly all market share for digital circuits; more recently MOSFETs have captured most analog and power applications as well, including modern clocked analog circuits, voltage regulators, amplifiers, power transmitters, motor drivers, etc.^ A power transistor amplifier - All About Circuits Forum .
  • class A power transistor amplifier - All About Circuits Forum 15 January 2010 9:09 UTC forum.allaboutcircuits.com [Source type: General]

^ Common collector application: voltage regulator.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ The current consumption of this amplifier is quite low and a power switch is not included.
  • Crystal Radio Circuits 15 January 2010 9:09 UTC www.techlib.com [Source type: FILTERED WITH BAYES]

Simplified operation

.The essential usefulness of a transistor comes from its ability to use a small signal applied between one pair of its terminals to control a much larger signal at another pair of terminals.^ Transistors function as current regulators by allowing a small current to control a larger current.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Capacitance exists between the terminals of a transistor.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ In a transistor switch a small Base current controls a much larger Collector current.

This property is called gain. .A transistor can control its output in proportion to the input signal, that is, can act as an amplifier.^ The transistor can output an amplified signal either from the collector or the emitter (or both).    9.

^ This is determined by measuring the signal to noise ratio (S/N) at the amplifier input and output.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ The input current is proportional to the output current.
  • transistor@Everything2.com 15 January 2010 9:09 UTC everything2.com [Source type: FILTERED WITH BAYES]

.Or, the transistor can be used to turn current on or off in a circuit as an electrically controlled switch, where the amount of current is determined by other circuit elements.^ Using a transistor as a switch .
  • Transistor Circuits 15 January 2010 9:09 UTC www.kpsec.freeuk.com [Source type: FILTERED WITH BAYES]

^ That means it takes an electric current to switch the transistor on or off.
  • How does a transistor work? A simple introduction and history from Explain that Stuff! 15 January 2010 9:09 UTC www.explainthatstuff.com [Source type: FILTERED WITH BAYES]

^ In other words, transistors restrict the amount of current passed according to a smaller, controlling current.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.The two types of transistors have slight differences in how they are used in a circuit.^ How are transistors used?
  • transistor Facts, information, pictures | Encyclopedia.com articles about transistor 15 January 2010 9:09 UTC www.encyclopedia.com [Source type: FILTERED WITH BAYES]

^ Circuit diagram for an amplifier using an n-p-n transistor.
  • n-p-n transistor (electronics) -- Britannica Online Encyclopedia 15 January 2010 9:09 UTC www.britannica.com [Source type: Reference]

^ This is the same as the circuit used to find the b of transistors.
  • Electronics I Experiment 9 Transistor Biasing 15 January 2010 9:09 UTC engr.astate.edu [Source type: Academic]

.A bipolar transistor has terminals labeled base, collector, and emitter.^ V be is the base-emitter voltage and V bc is the base-collector voltage.
  • Model NPN bipolar transistor using enhanced Ebers-Moll equations - Simulink 15 January 2010 9:09 UTC www.mathworks.com [Source type: Academic]

^ Alternatively, the transistor can be a pnp transistor with the collector and emitter being p doped and the base being n doped.
  • TRANSISTOR - Patent application - heterojunction bipolar transistor comprising a substrate 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

^ The transistor can be an npn transistor with the collector and emitter being n doped and the base being p doped.
  • TRANSISTOR - Patent application - heterojunction bipolar transistor comprising a substrate 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

.A small current at the base terminal (that is, flowing from the base to the emitter) can control or switch a much larger current between the collector and emitter terminals.^ Voltage Vbe Base-emitter voltage when the collector current is zero and the base current is Ib .
  • Model NPN bipolar transistor using enhanced Ebers-Moll equations - Simulink 15 January 2010 9:09 UTC www.mathworks.com [Source type: Academic]

^ Base Current verses Collector Current .

^ If connected “backwards” in a circuit, a base-collector current will fail to control current between collector and emitter.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.For a field-effect transistor, the terminals are labeled gate, source, and drain, and a voltage at the gate can control a current between source and drain.^ Process to separate the doping of polygate and source drain regions in dual gate field effect transistors .
  • Fermi threshold field effect transistor - Google Patent Search 15 January 2010 9:09 UTC www.google.com [Source type: News]

^ This "field effect" allows a current to flow and switches the transistor on: .
  • How does a transistor work? A simple introduction and history from Explain that Stuff! 15 January 2010 9:09 UTC www.explainthatstuff.com [Source type: FILTERED WITH BAYES]

^ MOS-type transistors - Field-effect transistors .
  • transistor (electronics) -- Britannica Online Encyclopedia 15 January 2010 9:09 UTC www.britannica.com [Source type: Reference]

.The image to the right represents a typical bipolar transistor in a circuit.^ Bipolar junction transistors are typically made of silicon and so they are very cheap to produce and purchase.
  • What is a Transistor - Electronics 15 January 2010 9:09 UTC www.reuk.co.uk [Source type: FILTERED WITH BAYES]

^ Equivalent circuit for the Ebers-Moll model of an npn bipolar junction transistor .
  • Bipolar Junction Transistors 15 January 2010 9:09 UTC ece-www.colorado.edu [Source type: Reference]

^ A typical current gain for a silicon bipolar transistor is 50 - 150.
  • Bipolar Junction Transistors 15 January 2010 9:09 UTC ece-www.colorado.edu [Source type: Reference]

.Charge will flow between emitter and collector terminals depending on the current in the base.^ Voltage Vbe Base-emitter voltage when the collector current is zero and the base current is Ib .
  • Model NPN bipolar transistor using enhanced Ebers-Moll equations - Simulink 15 January 2010 9:09 UTC www.mathworks.com [Source type: Academic]

^ Base Current verses Collector Current .

^ If connected “backwards” in a circuit, a base-collector current will fail to control current between collector and emitter.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.Since internally the base and emitter connections behave like a semiconductor diode, a voltage drop develops between base and emitter while the base current exists.^ Voltage Vbe Base-emitter voltage when the collector current is zero and the base current is Ib .
  • Model NPN bipolar transistor using enhanced Ebers-Moll equations - Simulink 15 January 2010 9:09 UTC www.mathworks.com [Source type: Academic]

^ If connected “backwards” in a circuit, a base-collector current will fail to control current between collector and emitter.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ V be is the base-emitter voltage and V bc is the base-collector voltage.
  • Model NPN bipolar transistor using enhanced Ebers-Moll equations - Simulink 15 January 2010 9:09 UTC www.mathworks.com [Source type: Academic]

.The amount of this voltage depends on the material the transistor is made from, and is referred to as VBE.^ If the transistor's voltage/current relationship changes with temperature, the amount of DC bias voltage necessary for the desired class of operation will change.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ One popular small-signal transistor, the 2N3903, is advertised as having a β ranging from 15 to 150 depending on the amount of collector current.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ The letters refer to the layers of semiconductor material used to make the transistor.
  • Transistor Circuits 15 January 2010 9:09 UTC www.kpsec.freeuk.com [Source type: FILTERED WITH BAYES]

Transistor as a switch

BJT used as an electronic switch, in grounded-emitter configuration.
.Transistors are commonly used as electronic switches, for both high power applications including switched-mode power supplies and low power applications such as logic gates.^ High Speed Logic Gate (25) .
  • Small Signal Transistor - Fairchild Semiconductor Site Search 15 January 2010 9:09 UTC www.fairchildsemi.com [Source type: Reference]

^ Our transistors are used as electronic switches for both high and low power usage.

^ Using a transistor as a switch .
  • Transistor Circuits 15 January 2010 9:09 UTC www.kpsec.freeuk.com [Source type: FILTERED WITH BAYES]

.In a grounded-emitter transistor circuit, such as the light-switch circuit shown, as the base voltage rises the base and collector current rise exponentially, and the collector voltage drops because of the collector load resistor.^ Voltage Vbe Base-emitter voltage when the collector current is zero and the base current is Ib .
  • Model NPN bipolar transistor using enhanced Ebers-Moll equations - Simulink 15 January 2010 9:09 UTC www.mathworks.com [Source type: Academic]

^ Base Current verses Collector Current .

^ If connected “backwards” in a circuit, a base-collector current will fail to control current between collector and emitter.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

The relevant equations:
VRC = ICE × RC, the voltage across the load (the lamp with resistance RC)
VRC + VCE = VCC, the supply voltage shown as 6V
.If VCE could fall to 0 (perfect closed switch) then Ic could go no higher than VCC / RC, even with higher base voltage and current.^ Input no voltage to the base.
  • THE TRANSISTOR 15 January 2010 9:09 UTC www.comphist.org [Source type: FILTERED WITH BAYES]

^ When the switch is closed a small current flows into the base (B) of the transistor.
  • Transistor Circuits 15 January 2010 9:09 UTC www.kpsec.freeuk.com [Source type: FILTERED WITH BAYES]

^ The saturation voltage is also lower for higher base drive current.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.The transistor is then said to be saturated.^ REVIEW: A transistor is said to be in its active mode if it is operating somewhere between fully on (saturated) and fully off (cutoff).
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ In this state of maximum circuit current, the transistor is said to be saturated .
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ In the fully ON state the voltage V CE across the transistor is almost zero and the transistor is said to be saturated because it cannot pass any more collector current Ic.
  • Transistor Circuits 15 January 2010 9:09 UTC www.kpsec.freeuk.com [Source type: FILTERED WITH BAYES]

.Hence, values of input voltage can be chosen such that the output is either completely off,[12] or completely on.^ As the input voltage increases, so does the output voltage.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ The input voltage controls the output current.
  • transistor@Everything2.com 15 January 2010 9:09 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ Either input can be driven (biased) to affect the operating point of both transistors in a complementary fashion, and therefore the output (collector) offset voltage.

.The transistor is acting as a switch, and this type of operation is common in digital circuits where only "on" and "off" values are relevant.^ This page explains the operation of transistors in circuits.
  • Transistor Circuits 15 January 2010 9:09 UTC www.kpsec.freeuk.com [Source type: FILTERED WITH BAYES]

^ Figure 14: Transistor switch circuit.

^ While we make some FETs, most of the parts are integrated circuit amplifiers and switches with internal transistors, coils, capacitors and resistors formed on Gallium Arsenide and operating from 500MHz to over 50 GHz.
  • Transistor Failure Rates - Elmers Forum at eHam.net 15 January 2010 9:09 UTC www.eham.net [Source type: General]

Transistor as an amplifier

Amplifier circuit, standard common-emitter configuration.
.The common-emitter amplifier is designed so that a small change in voltage in (Vin) changes the small current through the base of the transistor and the transistor's current amplification combined with the properties of the circuit mean that small swings in Vin produce large changes in Vout.^ Voltage Vbe Base-emitter voltage when the collector current is zero and the base current is Ib .
  • Model NPN bipolar transistor using enhanced Ebers-Moll equations - Simulink 15 January 2010 9:09 UTC www.mathworks.com [Source type: Academic]

^ Thus, the common-emitter amplifier is called an inverting amplifier circuit.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Figure 5: Configuration for the common emitter circuit .
  • Transistor I-V Characteristics 15 January 2010 9:09 UTC cnx.org [Source type: General]

.Various configurations of single transistor amplifier are possible, with some providing current gain, some voltage gain, and some both.^ Single Transistors are made for audio amplifiers.
  • New Transistor Series with Fine Patterning Process Technology, Panasonic Electric C 15 January 2010 9:09 UTC news.thomasnet.com [Source type: General]

^ A transistor amplifies current and can be used as a switch.
  • Transistor Circuits 15 January 2010 9:09 UTC www.kpsec.freeuk.com [Source type: FILTERED WITH BAYES]

^ What is this name, and what advantage does this configuration provide over a single transistor?
  • Bipolar transistor biasing circuits : Worksheet 15 January 2010 9:09 UTC www.allaboutcircuits.com [Source type: FILTERED WITH BAYES]

.From mobile phones to televisions, vast numbers of products include amplifiers for sound reproduction, radio transmission, and signal processing.^ It is used in electronic switches, as an amplifier in mobile phone to television for sound reproduction, radio transmission, signal processing, and integrated circuits.
  • Transistors, Transistors Manufacturers, Transistors Suppliers, Transistors Wholesale 15 January 2010 9:09 UTC www.digitivity.com [Source type: News]

^ Those few applications include radio frequency amplifiers.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Cellular phones are one example of systems which make extensive use of signal processing to better utilize bandwidth; micromechanical systems (MEMS) can make even more extensive use of on-chip signal processing.
  • final-report 15 January 2010 9:09 UTC www.princeton.edu [Source type: FILTERED WITH BAYES]

.The first discrete transistor audio amplifiers barely supplied a few hundred milliwatts, but power and audio fidelity gradually increased as better transistors became available and amplifier architecture evolved.^ SFT 151 first audio stage transistor .
  • Australian Semiconductor Manufacturers (Transistor History) 15 January 2010 9:09 UTC sites.google.com [Source type: FILTERED WITH BAYES]

^ Raytheon subsequently became the first manufacturer to mass-produce junction transistors.

^ Because the transistor is not conducting most of the time, power efficiencies are high for a class C amplifier.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.Modern transistor audio amplifiers of up to a few hundred watts are common and relatively inexpensive.^ Single Transistors are made for audio amplifiers.
  • New Transistor Series with Fine Patterning Process Technology, Panasonic Electric C 15 January 2010 9:09 UTC news.thomasnet.com [Source type: General]

^ Common emitter amplifier drives speaker with audio frequency signal.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ One of the few examples is “TR One, one transistor radio” TR One, Ch 9 with an amplified AM (amplitude modulation) detector.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

Comparison with vacuum tubes

.Prior to the development of transistors, vacuum (electron) tubes (or in the UK "thermionic valves" or just "valves") were the main active components in electronic equipment.^ Main Development of transistors .
  • transistor (electronics) -- Britannica Online Encyclopedia 15 January 2010 9:09 UTC www.britannica.com [Source type: Reference]

^ Comparison with vacuum tubes == Prior to the development of transistors, vacuum (electron) tubes (or in the UK “thermionic valves” or just “valves”) were the main active components in electronic equipment.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ For valve or vacuum tube gear, that is.
  • Transistor Failure Rates - Elmers Forum at eHam.net 15 January 2010 9:09 UTC www.eham.net [Source type: General]

Advantages

The key advantages that have allowed transistors to replace their vacuum tube predecessors in most applications are
.
  • Small size and minimal weight, allowing the development of miniaturized electronic devices.
  • Highly automated manufacturing processes, resulting in low per-unit cost.
  • Lower possible operating voltages, making transistors suitable for small, battery-powered applications.
  • No warm-up period for cathode heaters required after power application.
  • Lower power dissipation and generally greater energy efficiency.
  • Higher reliability and greater physical ruggedness.
  • Extremely long life.^ This is what the device is -- an electronically operating crystal.

    ^ Little heat energy dissipated makes energy efficiency high.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ Its small size, low heat generation, high reliability, and low power consumption made possible a breakthrough in the miniaturization of complex circuitry.
    • transistor (electronics) -- Britannica Online Encyclopedia 15 January 2010 9:09 UTC www.britannica.com [Source type: Reference]

    Some transistorized devices have been in service for more than 30 years.
  • Complementary devices available, facilitating the design of complementary-symmetry circuits, something not possible with vacuum tubes.
  • Insensitivity to mechanical shock and vibration, thus avoiding the problem of microphonics in audio applications.

Limitations

.
  • Silicon transistors do not operate at voltages higher than about 1,000 volts (SiC devices can be operated as high as 3,000 volts).^ Disadvantages === * Silicon transistors do not operate at voltages higher than about 1 kV, SiC go to 3 kV. * The electron mobility is higher in a vacuum, so that high power, high frequency operation is easier in tubes.
    • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

    ^ For transistors this is about 0.6 volts.
    • So I acquired this pair of vintage Yamaha M-45 Class A stereo amplifiers this afternoon... - Straight Dope Message Board 15 January 2010 9:09 UTC boards.straightdope.com [Source type: FILTERED WITH BAYES]

    ^ The 50-nanometer transistor - roughly 2,000 times smaller than...
    • transistor Facts, information, pictures | Encyclopedia.com articles about transistor 15 January 2010 9:09 UTC www.encyclopedia.com [Source type: FILTERED WITH BAYES]

    In contrast, electron tubes have been developed that can be operated at tens of thousands of volts.
  • High power, high frequency operation, such as that used in over-the-air television broadcasting, is better achieved in electron tubes due to improved electron mobility in a vacuum.
  • Silicon transistors are much more sensitive than electron tubes to an electromagnetic pulse, such as generated by an atmospheric nuclear explosion.

Types

BJT PNP symbol.svg PNP JFET P-Channel Labelled.svg P-channel
BJT NPN symbol.svg NPN JFET N-Channel Labelled.svg N-channel
BJT JFET
BJT and JFET symbols
JFET P-Channel Labelled.svg IGFET P-Ch Enh Labelled.svg IGFET P-Ch Enh Labelled simplified.svg IGFET P-Ch Dep Labelled.svg P-channel
JFET N-Channel Labelled.svg IGFET N-Ch Enh Labelled.svg IGFET N-Ch Enh Labelled simplified.svg IGFET N-Ch Dep Labelled.svg N-channel
JFET MOSFET enh MOSFET dep
JFET and IGFET symbols
Transistors are categorized by
.Thus, a particular transistor may be described as silicon, surface mount, BJT, NPN, low power, high frequency switch.^ The CMOS structure is popular because of its inherent lower power requirements, high operating clock speed, and ease of implementation at the transistor level.
  • Transistor Level Implementation of CMOS Combinational Logic Circuits 15 January 2010 9:09 UTC et.nmsu.edu [Source type: Reference]

^ HBTs provide faster switching speeds than silicon bipolar transistors mainly due to reduced base resistance and collector to substrate capacitance.
  • TRANSISTOR - Patent application - heterojunction bipolar transistor comprising a substrate 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

^ Its small size, low heat generation, high reliability, and low power consumption made possible a breakthrough in the miniaturization of complex circuitry.
  • transistor (electronics) -- Britannica Online Encyclopedia 15 January 2010 9:09 UTC www.britannica.com [Source type: Reference]

Bipolar junction transistor

.Bipolar transistors are so named because they conduct by using both majority and minority carriers.^ Bipolar transistors are so named because they conduct by using both majority and minority carriers.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ The next section will explore in more detail the use of bipolar transistors as switching elements.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Model NPN bipolar transistor using enhanced Ebers-Moll equations - Simulink Home .
  • Model NPN bipolar transistor using enhanced Ebers-Moll equations - Simulink 15 January 2010 9:09 UTC www.mathworks.com [Source type: Academic]

.The bipolar junction transistor (BJT), the first type of transistor to be mass-produced, is a combination of two junction diodes, and is formed of either a thin layer of p-type semiconductor sandwiched between two n-type semiconductors (an n-p-n transistor), or a thin layer of n-type semiconductor sandwiched between two p-type semiconductors (a p-n-p transistor).^ Raytheon subsequently became the first manufacturer to mass-produce junction transistors.

^ The Junction Transistor The n-p-n junction transistor consists of two n -type semiconductors (called the emitter and collector) separated by a thin layer of p -type semiconductor (called the base).
  • transistor Facts, information, pictures | Encyclopedia.com articles about transistor 15 January 2010 9:09 UTC www.encyclopedia.com [Source type: FILTERED WITH BAYES]

^ Junction transistors - MOS-type transistors .
  • transistor (electronics) -- Britannica Online Encyclopedia 15 January 2010 9:09 UTC www.britannica.com [Source type: Reference]

.This construction produces two p-n junctions: a base–emitter junction and a base–collector junction, separated by a thin region of semiconductor known as the base region (two junction diodes wired together without sharing an intervening semiconducting region will not make a transistor).^ V be is the base-emitter voltage and V bc is the base-collector voltage.
  • Model NPN bipolar transistor using enhanced Ebers-Moll equations - Simulink 15 January 2010 9:09 UTC www.mathworks.com [Source type: Academic]

^ Alternatively, the transistor can be a pnp transistor with the collector and emitter being p doped and the base being n doped.
  • TRANSISTOR - Patent application - heterojunction bipolar transistor comprising a substrate 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

^ The Junction Transistor The n-p-n junction transistor consists of two n -type semiconductors (called the emitter and collector) separated by a thin layer of p -type semiconductor (called the base).
  • transistor Facts, information, pictures | Encyclopedia.com articles about transistor 15 January 2010 9:09 UTC www.encyclopedia.com [Source type: FILTERED WITH BAYES]

.The BJT has three terminals, corresponding to the three layers of semiconductor - an emitter, a base, and a collector.^ Alternatively, the collector and emitter layers are p doped and the base layer is n doped.
  • TRANSISTOR - Patent application - heterojunction bipolar transistor comprising a substrate 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

^ Which terminals are emitter, base, and collector?
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ On the collector layer is a p + GaAs base layer 7.
  • TRANSISTOR - Patent application - heterojunction bipolar transistor comprising a substrate 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

.It is useful in amplifiers because the currents at the emitter and collector are controllable by a relatively small base current."^ Base Current verses Collector Current .

^ If connected “backwards” in a circuit, a base-collector current will fail to control current between collector and emitter.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ The small base current controls the larger collector current .
  • Transistor Circuits 15 January 2010 9:09 UTC www.kpsec.freeuk.com [Source type: FILTERED WITH BAYES]

[14] .In an NPN transistor operating in the active region, the emitter-base junction is forward biased (electrons and holes recombine at the junction), and electrons are injected into the base region.^ The transistor can be an npn transistor with the collector and emitter being n doped and the base being p doped.
  • TRANSISTOR - Patent application - heterojunction bipolar transistor comprising a substrate 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

^ Electrons are pulled from the emitter into the base—and then from the base into the collector.
  • How does a transistor work? A simple introduction and history from Explain that Stuff! 15 January 2010 9:09 UTC www.explainthatstuff.com [Source type: FILTERED WITH BAYES]

^ In an NPN transistor operating in the active region, the emitter-base junction is forward biased, and electrons are injected into the base region.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

.Because the base is narrow, most of these electrons will diffuse into the reverse-biased (electrons and holes are formed at, and move away from the junction) base-collector junction and be swept into the collector; perhaps one-hundredth of the electrons will recombine in the base, which is the dominant mechanism in the base current.^ Base Current verses Collector Current .

^ Because the base is narrow, most of these electrons will diffuse into the reverse-biased base-collector junction and be swept into the collector; perhaps one-hundredth of the electrons will recombine in the base, which is the dominant mechanism in the base current.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ The collector and base currents are: .
  • Model NPN bipolar transistor using enhanced Ebers-Moll equations - Simulink 15 January 2010 9:09 UTC www.mathworks.com [Source type: Academic]

.By controlling the number of electrons that can leave the base, the number of electrons entering the collector can be controlled.^ By controlling the number of electrons that can leave the base, the number of electrons entering the collector can be controlled.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ If connected “backwards” in a circuit, a base-collector current will fail to control current between collector and emitter.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Remember that bipolar transistors are current-controlled devices : they regulate collector current based on the existence of base-to-emitter current , not base-to-emitter voltage .
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

[14] .Collector current is approximately β (common-emitter current gain) times the base current.^ Base Current verses Collector Current .

^ The collector and emitter currents are approximately equal, since , so we find .

^ The current gain of a common-collector amplifier is equal to β plus 1.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.It is typically greater than 100 for small-signal transistors but can be smaller in transistors designed for high-power applications.^ Small-signal/general-purpose transistors .
  • Transistor Manufacturers & Suppliers 19 September 2009 23:26 UTC www.globalsources.com [Source type: FILTERED WITH BAYES]

^ The β for small signal transistors typically has a range of 100-300, power transistors: 20-50.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ We choose I C = 1mA, typical of a small-signal transistor circuit.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.Unlike the FET, the BJT is a low–input-impedance device.^ Unlike the FET, the BJT is a low–input-impedance device.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ Applying current in BJTs and voltage in FETs between the input and common terminals increases the conductivity between the common and output terminals, thereby controlling current flow between them.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ For low noise at narrow bandwidth the higher input resistance of the FET is advantageous.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

.Also, as the base–emitter voltage (Vbe) is increased the base–emitter current and hence the collector–emitter current (Ice) increase exponentially according to the Shockley diode model and the Ebers-Moll model.^ Base Current verses Collector Current .

^ Which terminals are emitter, base, and collector?
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ The switched (controlled) current goes between emitter and collector; the controlling current goes between emitter and base.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

Because of this exponential relationship, the BJT has a higher transconductance than the FET.
.Bipolar transistors can be made to conduct by exposure to light, since absorption of photons in the base region generates a photocurrent that acts as a base current; the collector current is approximately β times the photocurrent.^ Base Current verses Collector Current .

^ Base current regulates collector current.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ The three leads of a bipolar transistor are called the Emitter , Base , and Collector .
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.Devices designed for this purpose have a transparent window in the package and are called phototransistors.^ Devices designed for this purpose have a transparent window in the package and are called phototransistors.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

Field-effect transistor

.The field-effect transistor (FET), sometimes called a unipolar transistor, uses either electrons (in N-channel FET) or holes (in P-channel FET) for conduction.^ MOS-type transistors - Field-effect transistors .
  • transistor (electronics) -- Britannica Online Encyclopedia 15 January 2010 9:09 UTC www.britannica.com [Source type: Reference]

^ Fermi threshold field effect transistor .
  • Fermi threshold field effect transistor - Google Patent Search 15 January 2010 9:09 UTC www.google.com [Source type: News]

^ The result is a superconducting version of the field effect transistor (FET) - a mainstay of digital electronics.
  • First superconducting transistor promises PC revolution - tech - 03 December 2008 - New Scientist 15 January 2010 9:09 UTC www.newscientist.com [Source type: General]

.The four terminals of the FET are named source, gate, drain, and body (substrate).^ Process to separate the doping of polygate and source drain regions in dual gate field effect transistors .
  • Fermi threshold field effect transistor - Google Patent Search 15 January 2010 9:09 UTC www.google.com [Source type: News]

^ Although there are extra electrons in the n-type source and drain, they cannot flow from one to the other because of the holes in the p-type gate in between them.
  • How does a transistor work? A simple introduction and history from Explain that Stuff! 15 January 2010 9:09 UTC www.explainthatstuff.com [Source type: FILTERED WITH BAYES]

^ How about: SOURCE & DRAIN for the top and bottom, and GATE for the input.
  • Pnuematic CMOS Lecture 15 January 2010 9:09 UTC www.mine-control.com [Source type: Original source]

On most FETs, the body is connected to the source inside the package, and this will be assumed for the following description.
.In FETs, the drain-to-source current flows via a conducting channel that connects the source region to the drain region.^ In the non-saturated (or triode) region, the voltage drop across the drain-source terminals approaches zero volts as the magnitude of the voltage drop across the gate-source terminals approaches V DD - V SS .
  • Transistor Level Implementation of CMOS Combinational Logic Circuits 15 January 2010 9:09 UTC et.nmsu.edu [Source type: Reference]

^ Process to separate the doping of polygate and source drain regions in dual gate field effect transistors .
  • Fermi threshold field effect transistor - Google Patent Search 15 January 2010 9:09 UTC www.google.com [Source type: News]

^ Although there are extra electrons in the n-type source and drain, they cannot flow from one to the other because of the holes in the p-type gate in between them.
  • How does a transistor work? A simple introduction and history from Explain that Stuff! 15 January 2010 9:09 UTC www.explainthatstuff.com [Source type: FILTERED WITH BAYES]

.The conductivity is varied by the electric field that is produced when a voltage is applied between the gate and source terminals; hence the current flowing between the drain and source is controlled by the voltage applied between the gate and source.^ The collector is a current source: it does not source a voltage.    6.

^ A field effect transistor comprising: a semiconductor substrate having a first surface, and being doped at a first dopant density; a substrate contact for electrically contacting said substrate; means for applying a substrate bias voltage to said substrate contact; source and drain regions in said substrate at said first surface; a channel in said substrate at said first surface, between said source and drain regions, said channel being doped at a second dopant density and having a predetermined depth from said first surface and a predetermined length from said source to said drain; a gate insulating layer on said first surface adjacent said channel, said gate insulating layer having a predetermined thickness, at least said first and second dopant densities, said substrate bias voltage and said predetermined depth being selected to produce a threshold voltage for said field effect transistor which is independent of said predetermined length and said predetermined thickness; and source, drain and gate contacts for electrically contacting said source and drain regions and said gate insulating layer, respectively.
  • Fermi threshold field effect transistor - Google Patent Search 15 January 2010 9:09 UTC www.google.com [Source type: News]

^ A field effect transistor comprising: a semiconductor substrate of first conductivity type, having a first surface and being doped at a first dopant density N.sub.a ; source and drain regions of second conductivity type in said substrate at said first surface; a channel of said second conductivity type in said substrate at said first surface, between said source and drain regions; a gate insulating layer on said substrate at said first surface adjacent said channel; source and drain contacts for electrically contacting said source and drain, respectively; a gate contact for electrically contacting said gate insulating layer; and first and second substrate enhancement pocket regions in said semiconductor substrate, adjacent said source and drain regions respectively, said substrate enhancement pocket regions being of said first conductivity type and having a dopant density which is a factor times said first dopant density, said factor being selected to produce a continuous depletion region under said source, drain and channel regions at a second predetermined depth from said first surface.
  • Fermi threshold field effect transistor - Google Patent Search 15 January 2010 9:09 UTC www.google.com [Source type: News]

.As the gate–source voltage (Vgs) is increased, the drain–source current (Ids) increases exponentially for Vgs below threshold, and then at a roughly quadratic rate (I_{ds} \propto (V_{gs}-V_T)^2) (where VT is the threshold voltage at which drain current begins)[15] in the "space-charge-limited" region above threshold.^ As the gate–source voltage is increased, the drain–source current below threshold, and then at a roughly quadratic rate in the ”space-charge-limited” region above threshold.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ The collector is a current source: it does not source a voltage.    6.

^ In the non-saturated (or triode) region, the voltage drop across the drain-source terminals approaches zero volts as the magnitude of the voltage drop across the gate-source terminals approaches V DD - V SS .
  • Transistor Level Implementation of CMOS Combinational Logic Circuits 15 January 2010 9:09 UTC et.nmsu.edu [Source type: Reference]

A quadratic behavior is not observed in modern devices, for example, at the 65 nm technology node.[16]
.For low noise at narrow bandwidth the higher input resistance of the FET is advantageous.^ For low noise at narrow bandwidth the higher input resistance of the FET is advantageous.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ While the C-B (common-base) amplifier is known for wider bandwidth than the C-E (common-emitter) configuration, the low input impedance (10s of Ω) of C-B is a limitation for many applications.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Two advantages of junction transistors were reported to be a significantly lower noise figure coupled with higher gain.

.FETs are divided into two families: junction FET (JFET) and insulated gate FET (IGFET).^ Bipolar junction transistor, Field-effect transistor, Hetrojunction bipolar transistor, and Dual gate FETs is very important among all its type.
  • Transistors, Transistors Manufacturers, Transistors Suppliers, Transistors Wholesale 15 January 2010 9:09 UTC www.digitivity.com [Source type: News]

^ Like a junction transistor, a FET (field effect transistor) has three different terminals—but they have the names source (analagous to the emitter), drain (analagous to the collector), and gate (analagous to the base).
  • How does a transistor work? A simple introduction and history from Explain that Stuff! 15 January 2010 9:09 UTC www.explainthatstuff.com [Source type: FILTERED WITH BAYES]

^ We can turn this into an AND gate by just sticking yet another NOT on it since two negatives make a positive.
  • Pnuematic CMOS Lecture 15 January 2010 9:09 UTC www.mine-control.com [Source type: Original source]

.The IGFET is more commonly known as a metal–oxide–semiconductor FET (MOSFET), reflecting its original construction from layers of metal (the gate), oxide (the insulation), and semiconductor.^ Students in introductory electronic circuits classes can gain insight into the operation of these CMOS devices through a few exercises in constructing simple CMOS combinational logic circuits such as AND, NAND gates, OR, NOR gates and INVERTERS. These circuits are created using both p and n-channel Metal-Oxide Semiconductor Field Effect Transistors (MOSFET) connected in complementary configurations.
  • Transistor Level Implementation of CMOS Combinational Logic Circuits 15 January 2010 9:09 UTC et.nmsu.edu [Source type: Reference]

^ Silicon is a semiconductor , which means it's neither really a conductor (something like a metal that lets electricity flow) nor an insulator (something like plastic that stops electricity flowing).
  • How does a transistor work? A simple introduction and history from Explain that Stuff! 15 January 2010 9:09 UTC www.explainthatstuff.com [Source type: FILTERED WITH BAYES]

^ Also in other embodiments, wafer 101 may have a semiconductor on insulator (SOI) configuration where layer 103 is located over an insulator layer (not shown).
  • TRANSISTOR WITH DIFFERENTLY DOPED STRAINED CURRENT ELECTRODE REGION - Patent application 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

.Unlike IGFETs, the JFET gate forms a PN diode with the channel which lies between the source and drain.^ In the non-saturated (or triode) region, the voltage drop across the drain-source terminals approaches zero volts as the magnitude of the voltage drop across the gate-source terminals approaches V DD - V SS .
  • Transistor Level Implementation of CMOS Combinational Logic Circuits 15 January 2010 9:09 UTC et.nmsu.edu [Source type: Reference]

^ Although there are extra electrons in the n-type source and drain, they cannot flow from one to the other because of the holes in the p-type gate in between them.
  • How does a transistor work? A simple introduction and history from Explain that Stuff! 15 January 2010 9:09 UTC www.explainthatstuff.com [Source type: FILTERED WITH BAYES]

^ How about: SOURCE & DRAIN for the top and bottom, and GATE for the input.
  • Pnuematic CMOS Lecture 15 January 2010 9:09 UTC www.mine-control.com [Source type: Original source]

.Functionally, this makes the N-channel JFET the solid state equivalent of the vacuum tube triode which, similarly, forms a diode between its grid and cathode.^ Functionally, this makes the N-channel JFET the solid state equivalent of the vacuum tube triode which, similarly, forms a diode between its grid and cathode.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ See also: Zener diodes , IGBTs , Thyristors/thyristor modules , Switching spark gaps , Vacuum tubes .

^ Early tube-based technology did not switch fast enough for this role, leading the Bell team to use solid state diodes instead.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

.Also, both devices operate in the depletion mode, they both have a high input impedance, and they both conduct current under the control of an input voltage.^ Inputs A and C both assert high.
  • Transistor Level Implementation of CMOS Combinational Logic Circuits 15 January 2010 9:09 UTC et.nmsu.edu [Source type: Reference]

^ After all, it isn't the AC input signal that fuels thermal runaway: its the DC bias voltage required for a certain class of operation: that quiescent DC signal that we use to “trick” the transistor (fundamentally a DC device) into amplifying an AC signal.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Consequently the designer of an amplifier must build a device that supplies current to the speaker to drive it in both directions.
  • So I acquired this pair of vintage Yamaha M-45 Class A stereo amplifiers this afternoon... - Straight Dope Message Board 15 January 2010 9:09 UTC boards.straightdope.com [Source type: FILTERED WITH BAYES]

.Metal–semiconductor FETs (MESFETs) are JFETs in which the reverse biased PN junction is replaced by a metal–semiconductor Schottky-junction.^ Reverse voltages : As with diodes, bipolar transistors are rated for maximum allowable reverse-bias voltage across their PN junctions.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ The emitter-base PN junction has a slightly greater forward voltage drop than the collector-base PN junction, because of heavier doping of the emitter semiconductor layer.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ The reverse-biased base-collector junction normally blocks any current from going through the transistor between emitter and collector.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.These, and the HEMTs (high electron mobility transistors, or HFETs), in which a two-dimensional electron gas with very high carrier mobility is used for charge transport, are especially suitable for use at very high frequencies (microwave frequencies; several GHz).^ HBTs are used for digital and analogue microwave applications at high frequencies.
  • TRANSISTOR - Patent application - heterojunction bipolar transistor comprising a substrate 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

^ A transistor is a semiconductor device used to amplify or switch electronic signals, and it is the fundamental building block of modern electronic devices.
  • World's first molecular transistor created 15 January 2010 9:09 UTC news.webindia123.com [Source type: News]

^ The winning entry was an audio frequency meter using two CK722 transistors and four CK705 germanium diodes.

.Unlike bipolar transistors, FETs do not inherently amplify a photocurrent.^ Unlike bipolar transistors, FETs do not inherently amplify a photocurrent.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ Bipolar junction transistor, Field-effect transistor, Hetrojunction bipolar transistor, and Dual gate FETs is very important among all its type.
  • Transistors, Transistors Manufacturers, Transistors Suppliers, Transistors Wholesale 15 January 2010 9:09 UTC www.digitivity.com [Source type: News]

^ Beta : The ratio of collector current to base current, β is the fundamental parameter characterizing the amplifying ability of a bipolar transistor.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.Nevertheless, there are ways to use them, especially JFETs, as light-sensitive devices, by exploiting the photocurrents in channel–gate or channel–body junctions.^ Nevertheless, there are ways to use them, especially JFETs, as light-sensitive devices, by exploiting the photocurrents in channel–gate or channel–body junctions.
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ Nearly all JFETs are depletion-mode as the diode junctions would forward bias and conduct if they were enhancement mode devices; .
  • PS Audio - High-Performance Home Audio Equipment 15 January 2010 9:09 UTC www.psaudio.com [Source type: Reference]

^ The coherer was not very sensitive; it is amazing that such a bizarre device worked at all, but it was this device that was used as the detector when Marconi bridged the Atlantic in 1901.
  • Road to the Transistor 15 January 2010 9:09 UTC www.jmargolin.com [Source type: FILTERED WITH BAYES]

.FETs are further divided into depletion-mode and enhancement-mode types, depending on whether the channel is turned on or off with zero gate-to-source voltage.^ However, it can also function like a relay to amplify analog signals such as from an audio source, transferring a low voltage at the gate to a larger voltage at the drain.
  • Transistor: Definition and additional resources from ZDNet 15 January 2010 9:09 UTC dictionary.zdnet.com [Source type: General]

^ In the non-saturated (or triode) region, the voltage drop across the drain-source terminals approaches zero volts as the magnitude of the voltage drop across the gate-source terminals approaches V DD - V SS .
  • Transistor Level Implementation of CMOS Combinational Logic Circuits 15 January 2010 9:09 UTC et.nmsu.edu [Source type: Reference]

^ Instead, circuit designers usually place a coupling capacitor between the signal source and the voltage divider junction, like this: .
  • Bipolar transistor biasing circuits : Worksheet 15 January 2010 9:09 UTC www.allaboutcircuits.com [Source type: FILTERED WITH BAYES]

.For enhancement mode, the channel is off at zero bias, and a gate potential can "enhance" the conduction.^ A positive electrical bias on the emitter enhanced the conductivity of the germanium just beneath the collector point, amplifying the output current that flowed to it from the base.
  • IEEE Spectrum: The Lost History of the Transistor 15 January 2010 9:09 UTC spectrum.ieee.org [Source type: FILTERED WITH BAYES]

.For depletion mode, the channel is on at zero bias, and a gate potential (of the opposite polarity) can "deplete" the channel, reducing conduction.^ It will “turn on” in its active mode only when the input voltage is of the correct polarity to forward-bias the base-emitter diode, and only when that voltage is sufficiently high to overcome the diode's forward voltage drop.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ If the input signal bias for an amplifier is slightly negative (opposite of the bias polarity for class A operation), the output waveform will be further “clipped” than it was with class B biasing, resulting in an operation where the transistor spends most of the time in cutoff mode: .
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ The application of an electric field that reduces the barrier (a higher potential on the semiconductor side) permits electron flow, while reversal of that field further depletes the semiconductor of carriers, thus heightening the barrier to electron flow.
  • Road to the Transistor 15 January 2010 9:09 UTC www.jmargolin.com [Source type: FILTERED WITH BAYES]

.For either mode, a more positive gate voltage corresponds to a higher current for N-channel devices and a lower current for P-channel devices.^ Notice too that the gates for the p- and n-channel devices differ.
  • Transistor Level Implementation of CMOS Combinational Logic Circuits 15 January 2010 9:09 UTC et.nmsu.edu [Source type: Reference]

^ This changing voltage drop across the resistor--caused by the changing collector current--will change correspondingly to the "base" current.  Now follow me, just a few more words, and You've got it!

^ However, let us pretend that it does: the "collector" is a high impedance current source and if a resistor (the load resistor) is connected between the "collector" and the positive supply, a voltage is seen at the collector.

.Nearly all JFETs are depletion-mode as the diode junctions would forward bias and conduct if they were enhancement mode devices; most IGFETs are enhancement-mode types.^ This part makes sense, since the electrons are flowing from the N-type emitter to the P-type base: the junction is obviously forward-biased.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ They held the future in their hands - a device that would replace vacuum tubes in 10 years, and 60 years later has transformed electronics.
  • The transistor at 60 - Technology - smh.com.au 15 January 2010 9:09 UTC www.smh.com.au [Source type: News]

^ What happens in a transistor is this: the reverse bias of the base-collector junction prevents collector current when the transistor is in cutoff mode (that is, when there is no base current).
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

Other transistor types

.
  • Point-contact transistor, first kind of transistor ever constructed
  • Bipolar junction transistor (BJT)
    • Heterojunction bipolar transistor, up to 100s GHz, common in modern ultrafast and RF circuits
    • Grown-junction transistor, first kind of BJT
    • Alloy-junction transistor, improvement of grown-junction transistor
    • Drift-field transistor
    • Avalanche transistor
    • Darlington transistors are two BJTs connected together to provide a high current gain equal to the product of the current gains of the two transistors.
    • Insulated gate bipolar transistors (IGBTs) use a medium power IGFET, similarly connected to a power BJT, to give a high input impedance.^ The current gain of a common-collector amplifier is equal to β plus 1.
      • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

      ^ Send me the latest products for Power Transistor .

      ^ Base-bias by its self is not suitable for high emitter currents, as used in power amplifiers.
      • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

      .Power diodes are often connected between certain terminals depending on specific use.^ Staged” amplifiers are often used to achieve higher power gains than what would be possible using a single transistor as in Figure below .
      • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

      ^ The collector appears to output a voltage when a resistor is connected between it and power.    7.

      ^ However, this “collector-emitter saturation voltage” will be fairly low, around several tenths of a volt, depending on the specific transistor used.
      • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

      IGBTs are particularly suitable for heavy-duty industrial applications. The Asea Brown Boveri (ABB) 5SNA2400E170100 illustrates just how far power semiconductor technology has advanced.[17] .Intended for three-phase power supplies, this device houses three NPN IGBTs in a case measuring 38 by 140 by 190 mm and weighing 1.5 kg.^ Many power device datasheets include a dissipation versus case termperaure graph.
      • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

      ^ Figure below shows several standardized package types for three-terminal semiconductor devices, any of which may be used to house a bipolar transistor.
      • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

      ^ NPN Transistor with Maximum Low Current of 100mA and Power Supply of 65V .

      .Each IGBT is rated at 1,700 volts and can handle 2,400 amperes.
    • Photo transistor
  • Field-effect transistor
  • Spacistor
  • Diffusion transistor, formed by diffusing dopants into semiconductor substrate; can be both BJT and FET
  • Unijunction transistors can be used as simple pulse generators.^ This is a simple PN junction but there are a number of special use diodes out there.

    ^ One compromise was the necessity of using a 15 volt battery instead of a 1.5 volt one.

    ^ A transistor is formed by providing a semiconductor layer and forming a control electrode overlying the semiconductor layer.
    • TRANSISTOR WITH DIFFERENTLY DOPED STRAINED CURRENT ELECTRODE REGION - Patent application 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

    .They comprise a main body of either P-type or N-type semiconductor with ohmic contacts at each end (terminals Base1 and Base2).^ In further embodiments of the invention (not shown), the multilayer semiconductor wafer 17 comprises a grading layer 14 between the contact layer 12 and upper emitter layer 9.
    • TRANSISTOR - Patent application - heterojunction bipolar transistor comprising a substrate 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

    ^ Preferably, the method further comprises the step of depositing an ohmic metal contact on the emitter.
    • TRANSISTOR - Patent application - heterojunction bipolar transistor comprising a substrate 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

    ^ A multilayer semiconductor wafer as claimed in claim 25, further comprising an InGaAs contact layer on the upper emitter layer.
    • TRANSISTOR - Patent application - heterojunction bipolar transistor comprising a substrate 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

    .A junction with the opposite semiconductor type is formed at a point along the length of the body for the third terminal (Emitter).
  • Single-electron transistors (SET) consist of a gate island between two tunnelling junctions.^ The P-type emitter corresponds to “pointing” end of the base-emitter junction the emitter.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ Bipolar junction transistor, Field-effect transistor, Hetrojunction bipolar transistor, and Dual gate FETs is very important among all its type.
    • Transistors, Transistors Manufacturers, Transistors Suppliers, Transistors Wholesale 15 January 2010 9:09 UTC www.digitivity.com [Source type: News]

    ^ Since a transistor consists of two PN junctions (between base and emitter and between base and collector) the resistance of these in both directions can be checked.
    • UK Vintage Radio Repair and Restoration - Transistor Faults, Testing and Replacement 15 January 2010 9:09 UTC www.vintage-radio.com [Source type: FILTERED WITH BAYES]

    .The tunnelling current is controlled by a voltage applied to the gate through a capacitor.^ Gate: used to control current flow in the transistor.
    • The transistor at 60 - Technology - smh.com.au 15 January 2010 9:09 UTC www.smh.com.au [Source type: News]

    ^ Quiescent current, for example, is the amount of current in a circuit with zero input signal voltage applied.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ Now if we apply, say, an AC sinusoid to the base circuit (through a capacitor), the collector current--when seen as a large AC signal voltage at the collector--will be linear and undistorted.  .

    [18]
  • .
  • Nanofluidic transistor, controls the movement of ions through sub-microscopic, water-filled channels.^ A relatively small flow of electrons sent through the base of the transistor has the ability to exert control over a much larger flow of electrons through the collector.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ For the sake of illustration, let's insert a transistor in place of the switch to show how it can control the flow of electrons through the lamp.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ Since it is the current through the lamp that we want to control, we must position the collector and emitter of our transistor where the two contacts of the switch were.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    .Nanofluidic transistor, the basis of future chemical processors
  • Multigate devices
  • Junctionless Nanowire Transistor (JNT), developed at Tyndall National Institute in Ireland, was the first transistor successfully fabricated without junctions.^ Shockley develops first semiconductor transistor.
    • The transistor at 60 - Technology - smh.com.au 15 January 2010 9:09 UTC www.smh.com.au [Source type: News]

    ^ Junction capacitance limits high frequency gain of a transistor.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ Bipolar junction transistor, Field-effect transistor, Hetrojunction bipolar transistor, and Dual gate FETs is very important among all its type.
    • Transistors, Transistors Manufacturers, Transistors Suppliers, Transistors Wholesale 15 January 2010 9:09 UTC www.digitivity.com [Source type: News]

    (Even MOSFETs have junctions, although it's gate is electrically insulated from the region the gate controls.) .Junctions are difficult and expensive to fabricate, and, because they are a significant source of current leakage, they waste significant power and generate significant waste heat.^ And the faster they get, the more heat they generate.
    • Transistor Story. How did we get it ? 15 January 2010 9:09 UTC www.phils.com.au [Source type: Original source]

    ^ It is called the common-base configuration because (DC power source aside), the signal source and the load share the base of the transistor as a common connection point shown in Figure below .
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ The current source does not model the fact that its source of energy is a external power supply, similar to an amplifier.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    Eliminating them held the promise of cheaper and denser microchips. .The JNT uses a simple nanowire of silicon surrounded by an electrically-isolated "wedding ring" that acts to gate the flow of electrons through the wire.^ The Explorer I instrumentation payload used transistor electronics, consisting of both germanium and silicon devices.
    • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

    ^ The covered portion 28 is electrically isolated by implant isolation of the surrounding exposed portion of subcollector 29.
    • TRANSISTOR - Patent application - heterojunction bipolar transistor comprising a substrate 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

    ^ Gate: used to control current flow in the transistor.
    • The transistor at 60 - Technology - smh.com.au 15 January 2010 9:09 UTC www.smh.com.au [Source type: News]

    This method has been described as akin to squeezing a garden hose to gate the flow of water through the hose.

Part numbers

.The types of some transistors can be parsed from the part number.^ Noise figure varies with the transistor type (part number).
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ The only way to be sure which lead is which is by a meter check, or by referencing the manufacturer's “data sheet” documentation on that particular part number of transistor.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ He has conducted detailed and original research on a number of important transistor types and early companies and, importantly, this work is presented in a very readable style.
  • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

There are three major semiconductor naming standards; in each the alphanumeric prefix provides clues to type of the device:
.Japanese Industrial Standard (JIS) has a standard for transistor part numbers.^ The only way to be sure which lead is which is by a meter check, or by referencing the manufacturer's “data sheet” documentation on that particular part number of transistor.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ The current number of transistors the (semiconductor) industry churns out each year is 10 to the 18 th power, or .
  • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

^ Noise figure varies with the transistor type (part number).
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

They begin with "2S"[19], e.g. 2SD965, but sometimes the "2S" prefix is not marked on the package - a 2SD965 might only be marked "D965"; a 2SC1815 might be listed by a supplier as simply "C1815". This series sometimes has suffixes (such as "R", "O", "BL"... standing for "Red", "Orange", "Blue" etc...) to denote variants, such as tighter hFE (gain) groupings.
Beginning of Part Number Type of Transistor
2SA high frequency PNP BJTs
2SB audio frequency PNP BJTs
2SC high frequency NPN BJTs
2SD audio frequency NPN BJTs
2SJ P-channel FETs (both JFETs and MOSFETs)
2SK N-channel FETs (both JFETs and MOSFETs)
.The Pro Electron part numbers begin with two letters: the first gives the semiconductor type (A for Germanium, B for Silicon, and C for materials like GaAs); the second letter denotes the intended use (A for diode, C for general-purpose transistor, etc).^ We need to give names to these two different types of transistors.
  • Pnuematic CMOS Lecture 15 January 2010 9:09 UTC www.mine-control.com [Source type: Original source]

^ Small-signal/general-purpose transistors .
  • Transistor Manufacturers & Suppliers 19 September 2009 23:26 UTC www.globalsources.com [Source type: FILTERED WITH BAYES]

^ Noise figure varies with the transistor type (part number).
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.A 3-digit sequence number (or one letter then 2 digits, for industrial types) follows (and, with early devices, indicated the case type - just as the older system for vacuum tubes used the last digit or two to indicate the number of pins, and the first digit or two for the filament voltage).^ It has no vacuum, no filament, no glass tube.

^ Vacuum tubes (old ones) .
  • Transistor Stock Photos and Images. 794 Transistor pictures and royalty free photography available to search from over 100 stock photo brands. 19 September 2009 23:26 UTC www.fotosearch.com [Source type: General]

^ I swapped out that 14 pin voltage > > > > regulator chip with a new one "just in case."
  • Jurassic Park - No 5V, Left Sling "Held" and Blowing F5 - rec.games.pinball | Google Groups 15 January 2010 9:09 UTC groups.google.com [Source type: FILTERED WITH BAYES]

.A letter or other code to indicate transistor gain (e.g.^ Some other attributes are: It has a voltage gain of less than one (Gv ~ .95); it is not easy to cutoff, or saturated the transistor.

^ This means, among other things, that we could replace the transistor in a common-collector amplifier with one having a different β and not see any significant changes in voltage gain.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ This presumption is indeed correct: the current gain for a common-collector amplifier is quite large, larger than any other transistor amplifier configuration.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

."C" for high gain) or zener tolerance and voltage, etc, may follow.^ The C-B stage provides a high voltage gain.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ A second set of SPICE analyses (circuit in Figure below ) with an AC signal source (and DC bias voltage) tells the same story: a high voltage gain .
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ We now have a moderately high input impedance C-E stage without suffering the Miller effect, but no dB voltage gain.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

The more common prefixes are:
Prefix class Usage Example
AC Germanium small signal transistor AC126
AF Germanium RF transistor AF117
BC Silicon, small signal transistor ("allround") BC548B
BD Silicon, power transistor BD139
BF Silicon, RF (high frequency) BJT or FET BF245
BS Silicon, switching transistor (BJT or MOSFET) BS170
BL Silicon, high frequency, high power (for transmitters) BLW34
BU Silicon, high voltage (for television Horizontal Deflection circuits) BU508
.The JEDEC transistor device numbers usually start with 2N, indicating a three-terminal device (dual-gate Field Effect Transistors are four-terminal devices, so begin with 3N), then a 2, 3 or 4-digit sequential number with no significance as to device properties (although low numbers tend to be Germanium devices, because early transistors were mainly Germanium).^ Wanneer een recht koolstofskelet werd gebruikt als gate, werd de transistor spanningsafhankelijk geleidend, maar het effect was gering.
  • Onderzoekers ontwikkelen moleculaire transistor | Core | Tweakers.net Nieuws 15 January 2010 9:09 UTC tweakers.net [Source type: General]

^ The winning entry was an audio frequency meter using two CK722 transistors and four CK705 germanium diodes.

^ The germanium transistors were manufactured as the "grown junction" type, starting with huge crystals produced in this TI laboratory ( Automation , Nov., 1955, pp.48-53).
  • Regency TR-1 Transistor Radio Facts and Figures 15 January 2010 9:09 UTC people.msoe.edu [Source type: General]

.For example 2N3055 is a silicon NPN power transistor, 2N1301 is a PNP germanium switching transistor.^ NPN transistor switch, (c) PNP transistor switch.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ PNP Transistor with 625mW Power Dissipation .

^ NPN transistor as a simple switch.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

A letter suffix (such as "A") is sometimes used to indicate a newer variant, but rarely gain groupings.

Other Schemes

Manufacturers of devices may have their own proprietary numbering system, for example CK722. .Note that a manufacturer's prefix (like "MPF" in MPF102, which originally would denote a Motorola FET) now is an unreliable indicator of who made the device.^ This revolution made possible the design and manufacture of lightweight, inexpensive electronic devices that we now take for granted.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Youll also read (and hear) the details of the development of the now-standard TO-3 diamond shaped power transistor case style, a first for Motorola in 1955 and since used to manufacture billions of devices.
  • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

.Some proprietary naming schemes adopt parts of other naming schemes, for example a PN2222A is a (possibly Fairchild Semiconductor) 2N2222A in a plastic case (but a PN108 is a plastic version of a BC108, not a 2N108, while the PN70 is unrelated to other devices).^ There are many other semiconductor devices other than bipolar transistors which have three connection points.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Some collectors believe the logo was converted to foil to allow other brand names to be affixed to the plastic case, as in this Bulova 250 example.
  • Regency TR-1 Transistor Radio Facts and Figures 15 January 2010 9:09 UTC people.msoe.edu [Source type: General]

^ Lets give some names to the different parts of this thing.
  • Pnuematic CMOS Lecture 15 January 2010 9:09 UTC www.mine-control.com [Source type: Original source]

Military part numbers sometimes are assigned their own codes, such as the British Military CV Naming System.
.Manufacturers buying large numbers of similar parts may have them supplied with "house numbers", identifying a particular purchasing specification and not necessarily a device with a standardized registered number.^ The only way to be sure which lead is which is by a meter check, or by referencing the manufacturer's “data sheet” documentation on that particular part number of transistor.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ It is impossible to positively identify a three-terminal semiconductor device without referencing the part number printed on it, or subjecting it to a set of electrical tests.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Each integrated circuit may include a large number of transistors similar to that shown in FIG. 9 with some being N-channel transistors and others being P-channel transistors.
  • TRANSISTOR WITH DIFFERENTLY DOPED STRAINED CURRENT ELECTRODE REGION - Patent application 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

For example, an HP part 1854,0053 is a (JEDEC) 2N2218 transistor[20][21] which is also assigned the CV number: CV7763[22]

Problems With Naming

.With so many independent naming schemes, and the abbreviation of part numbers when printed on the devices, ambiguity sometimes occurs.^ It is impossible to positively identify a three-terminal semiconductor device without referencing the part number printed on it, or subjecting it to a set of electrical tests.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ These units have the date code printed perpendicular to the leads just above the case bottom on the same side as the type number and Raytheon name.

^ Many thanks to Dave Larson for the generous donation to the museum of these transistors (and a number of other related devices).
  • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

.For example two different devices may be marked "J176" (one the 2SJ176 low-power Junction FET, the other a higher-powered MOSFET J176).^ In one embodiment, recesses 201 and 203 are formed with a dry etch chemistry including HBr and Cl 2 , but may be etched by other techniques or with other etch chemistries in other embodiments.
  • TRANSISTOR WITH DIFFERENTLY DOPED STRAINED CURRENT ELECTRODE REGION - Patent application 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

^ However in other embodiments, structures 701 and 703 may have a different atomic percent.
  • TRANSISTOR WITH DIFFERENTLY DOPED STRAINED CURRENT ELECTRODE REGION - Patent application 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

^ In one embodiment, regions 2201 and 2203 have a thickness in the range of 100-600 angstroms, but may have other thickness in other embodiments.
  • TRANSISTOR WITH DIFFERENTLY DOPED STRAINED CURRENT ELECTRODE REGION - Patent application 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

.As older "through-hole" transistors are given Surface-Mount packaged counterparts, they tend to be assigned many different part numbers because manufacturers have their own systems to cope with the variety in pinout arrangements and options for dual or matched NPN+PNP devices in one pack.^ NPN transistor switch, (c) PNP transistor switch.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Transistor manufactures sometimes use their own numbering systems for transistors they develop on their own.

^ REVIEW: Bipolar transistors are so named because the controlled current must go through two types of semiconductor material: P and N. The current consists of both electron and hole flow, in different parts of the transistor.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.So even when the original device (such as a 2N3904) may have been assigned by a standards authority, and well known by engineers over the years, the new versions are far from standardised in their naming.^ Even after 10 to 12 years the alloy process was still not very well controlled.

^ Post Reply e144539 Jan 27, 2007 - 3:01 AM Well this news is more than 3 years old, but I guess they have a working prototype now.
  • Intel Reinvents the Transistor | Betanews 15 January 2010 9:09 UTC www.betanews.com [Source type: General]

^ Figure below shows several standardized package types for three-terminal semiconductor devices, any of which may be used to house a bipolar transistor.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

Construction

Semiconductor material

.The first BJTs were made from germanium (Ge).^ The first experimental semiconductor device was actually made of another material called germanium.

^ For example, if layer 103 is made of silicon germanium with a first concentration of germanium, stressors 301 and 303 may be made of silicon germanium with a higher concentration of germanium to increase the natural lattice constant over the lattice constant of layer 103.
  • TRANSISTOR WITH DIFFERENTLY DOPED STRAINED CURRENT ELECTRODE REGION - Patent application 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

.Silicon (Si) types currently predominate but certain advanced microwave and high performance versions now employ the compound semiconductor material gallium arsenide (GaAs) and the semiconductor alloy silicon germanium (SiGe).^ Substrates are the third major material; historically Intel has used silicon or silicon germanium (SiGe), and the industry has experimented with gallium arsenide.
  • Intel Reinvents the Transistor | Betanews 15 January 2010 9:09 UTC www.betanews.com [Source type: General]

^ The first experimental semiconductor device was actually made of another material called germanium.

^ Replacing silicon dioxide with the hafnium compound lets Intel go ahead and thicken the gate layer, which in turn naturally increases the amount of "on" current.
  • Intel Reinvents the Transistor | Betanews 15 January 2010 9:09 UTC www.betanews.com [Source type: General]

.Single element semiconductor material (Ge and Si) is described as elemental.^ The first letter indicates the material: A = Ge B = Si C = GaAs R = compound materials.

Rough parameters for the most common semiconductor materials used to make transistors are given in the table below; it must be noted that these parameters will vary with increase in temperature, electric field, impurity level, strain, and sundry other factors:
Semiconductor material characteristics
Semiconductor
material
Junction forward
voltage
V @ 25 °C
Electron mobility
m2/(V·s) @ 25 °C
Hole mobility
m2/(V·s) @ 25 °C
Max. junction temp.
°C
Ge 0.27 0.39 0.19 70 to 100
Si 0.71 0.14 0.05 150 to 200
GaAs 1.03 0.85 0.05 150 to 200
Al-Si junction 0.3 150 to 200
.The junction forward voltage is the voltage applied to the emitter-base junction of a BJT in order to make the base conduct a specified current.^ Like any PN junction, the base-emitter junction of a BJT only "wants" to conduct current in one direction.
  • Bipolar transistor biasing circuits : Worksheet 15 January 2010 9:09 UTC www.allaboutcircuits.com [Source type: FILTERED WITH BAYES]

^ Diode junction 0.7 V maintains constant base voltage, and constant base current.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Voltage collector to emitter vs collector current for various base currents.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.The current increases exponentially as the junction forward voltage is increased.^ The emitter-base PN junction has a slightly greater forward voltage drop than the collector-base PN junction, because of heavier doping of the emitter semiconductor layer.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ If the hotter transistor draws more current, the voltage drop across the ballast resistor increases— negative feedback.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Manufacturers will specify the maximum voltage drop of a transistor at saturation, both between the collector and emitter, and also between base and emitter (forward voltage drop of that PN junction).
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.The values given in the table are typical for a current of 1 mA (the same values apply to semiconductor diodes).^ The value of internal resistance R E is a function of emitter current I E , Table below .
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Current through the diode is described by a simple equation: power supply voltage minus diode voltage (almost a constant value), divided by the resistance of R bias .
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ In other words, transistor emitter current will closely equal diode current at any given time.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.The lower the junction forward voltage the better, as this means that less power is required to "drive" the transistor.^ So, as long as the average current requirements over time, including the down time, is less than the maximum current possible out of the power supply, then we ought to be able to build this optimization.
  • Pnuematic CMOS Lecture 15 January 2010 9:09 UTC www.mine-control.com [Source type: Original source]

^ Most power transistors are rated at half or less than the listed wattage.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Calculate the potentiometer wiper voltage (V bias ) required to maintain the transistor right at the threshold between cutoff and active mode.
  • Bipolar transistor biasing circuits : Worksheet 15 January 2010 9:09 UTC www.allaboutcircuits.com [Source type: FILTERED WITH BAYES]

.The junction forward voltage for a given current decreases with increase in temperature.^ If both junction voltage and temperature are held constant, then the PN junction current will be constant.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Leakage current I CO and β increase with temperature.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Unfortunately, though, the relationship between base-emitter voltage and base-emitter current changes with temperature, as predicted by the “diode equation.” As the transistor heats up, there will be less of a forward voltage drop across the base-emitter junction for any given current.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

For a typical silicon junction the change is −2.1 mV/°C.[23]
The density of mobile carriers in the channel of a MOSFET is a function of the electric field forming the channel and of various other phenomena such as the impurity level in the channel. .Some impurities, called dopants, are introduced deliberately in making a MOSFET, to control the MOSFET electrical behavior.^ Unfortunately, using a current source to model the transistor's current-controlling behavior can be misleading: in no way will the transistor ever act as a source of electrical energy.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Impurities are added to each layer to create a specific electrical positive or negative charged behavior.

.The electron mobility and hole mobility columns show the average speed that electrons and holes diffuse through the semiconductor material with an electric field of 1 volt per meter applied across the material.^ REVIEW: Bipolar transistors are so named because the controlled current must go through two types of semiconductor material: P and N. The current consists of both electron and hole flow, in different parts of the transistor.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ For the sake of illustration, let's insert a transistor in place of the switch to show how it can control the flow of electrons through the lamp.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ In other words, two types of charge carriers -- electrons and holes -- comprise this main current through the transistor.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.In general, the higher the electron mobility the speedier the transistor.^ With some N-channel transistors, a tensile strain in the channel direction may provide for increased electron mobility in the channel.
  • TRANSISTOR WITH DIFFERENTLY DOPED STRAINED CURRENT ELECTRODE REGION - Patent application 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

.The table indicates that Ge is a better material than Si in this respect.^ The first letter indicates the material: A = Ge B = Si C = GaAs R = compound materials.

However, Ge has four major shortcomings compared to silicon and gallium arsenide:
  • Its maximum temperature is limited;
  • it has relatively high leakage current;
  • it cannot withstand high voltages;
  • it is less suitable for fabricating integrated circuits.
.Because the electron mobility is higher than the hole mobility for all semiconductor materials, a given bipolar NPN transistor tends to be swifter than an equivalent PNP transistor type.^ NPN transistor switch, (c) PNP transistor switch.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ High temperature is the mortal enemy of all semiconductor devices, and bipolar transistors tend to be more susceptible to thermal damage than most.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ REVIEW: Bipolar transistors are so named because the controlled current must go through two types of semiconductor material: P and N. The current consists of both electron and hole flow, in different parts of the transistor.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

GaAs has the highest electron mobility of the three semiconductors. .It is for this reason that GaAs is used in high frequency applications.^ The solution to the junction capacitance problem is to select a high frequency transistor for wide bandwidth applications— RF (radio frequency) or microwave transistor.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ The largest commercial application for transistors has been in hearing aids, in which the benefits of miniaturization, long battery life and high reliability have justified their use.

.A relatively recent FET development, the high electron mobility transistor (HEMT), has a heterostructure (junction between different semiconductor materials) of aluminium gallium arsenide (AlGaAs)-gallium arsenide (GaAs) which has twice the electron mobility of a GaAs-metal barrier junction.^ REVIEW: Bipolar transistors are so named because the controlled current must go through two types of semiconductor material: P and N. The current consists of both electron and hole flow, in different parts of the transistor.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ This forward voltage difference is due to the disparity in doping concentration between the emitter and collector regions of the transistor: the emitter is a much more heavily doped piece of semiconductor material than the collector, causing its junction with the base to produce a higher forward voltage drop.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ An interesting sidebar reads as follows: "Bell Telephone Laboratories recent announcement of a new electronic component - the "Transistor" has started many "back of the shop" experiments.

.Because of their high speed and low noise, HEMTs are used in satellite receivers working at frequencies around 12 GHz.^ The common-base arrangement is sometimes used in RF (radio frequency) circuits to match a low impedance source, for example, a 50 Ω coaxial cable feed.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Low frequency: With AC coupling, the high-pass filtering of the coupling capacitor distorts the square wave's shape so that what is seen is not an accurate representation of the real signal.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Because of manufacturing difficulties at this early stage of development (and obviously its high cost), the CK703 was not produced or used in significant numbers.

Max. junction temperature values represent a cross section taken from various manufacturers' data sheets. .This temperature should not be exceeded or the transistor may be damaged.^ High temperature is the mortal enemy of all semiconductor devices, and bipolar transistors tend to be more susceptible to thermal damage than most.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Transistor inputs to analog integrated circuits also have a V EB rating, which if exceeded will cause damage, no zenering of the inputs is allowed.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.Al-Si junction refers to the high-speed (aluminum-silicon) semiconductor-metal barrier diode, commonly known as a Schottky diode.^ Semiconductor applications Semiconductor theory Energy bands Covalent bonding Doping process Semiconductor diode PN Junction operation Junction Barrier PN Junction application Diode characteristics Diode identification Diode maintenance Summary Answers .

^ What the "T-cap" or Transfer Capacitor really is, is a metal-insulated dielectric junction semiconductor based on silver alkane.
  • Transistor Story. How did we get it ? 15 January 2010 9:09 UTC www.phils.com.au [Source type: Original source]

^ Basics Crystal Structure Physical Properties Semiconductor Physics Physical Properties in detail Electrical Properties of Semiconductors The p-n Junction The MOS structure Metal-Semiconductor Junctions Java Applets Illustrations More Semiconductor Applets .

.This is included in the table because some silicon power IGFETs have a parasitic reverse Schottky diode formed between the source and drain as part of the fabrication process.^ We may apply an AC voltage input signal between the base and emitter, but electrons cannot flow in that circuit during the part of the cycle that reverse-biases the base-emitter diode junction.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ It is called the common-base configuration because (DC power source aside), the signal source and the load share the base of the transistor as a common connection point shown in Figure below .
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.This diode can be a nuisance, but sometimes it is used in the circuit.^ The common-base arrangement is sometimes used in RF (radio frequency) circuits to match a low impedance source, for example, a 50 Ω coaxial cable feed.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Some circuit designers use discrete BJTs as 7 V zener diodes with a series current limiting resistor.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

Packaging

Through-hole transistors (tape measure marked in centimetres)
.Transistors come in many different packages (chip carriers) (see images).^ This means, among other things, that we could replace the transistor in a common-collector amplifier with one having a different β and not see any significant changes in voltage gain.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ This yields an estimate of many billions of transistors produced every day, just in processor chips alone.
  • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

^ Bipolar transistors come in a wide variety of physical packages.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.The two main categories are through-hole (or leaded), and surface-mount, also known as surface mount device (SMD).^ In other words, two types of charge carriers -- electrons and holes -- comprise this main current through the transistor.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.The ball grid array (BGA) is the latest surface mount package (currently only for large transistor arrays).^ Here we see the transistor functioning not only as a switch, but as a true amplifier : using a relatively low-power signal to control a relatively large amount of power.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Large signal amplifiers are not 100% linear because transistor characteristics like β are not constant, but vary with collector current.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ First is the fact that when used in this manner, the switch contacts need only handle what little base current is necessary to turn the transistor on; the transistor itself handles most of the lamp's current.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

It has solder "balls" on the underside in place of leads. .Because they are smaller and have shorter interconnections, SMDs have better high frequency characteristics but lower power rating.^ Power Transistor with 160V Collector-base Voltage and High Transition Frequency .

^ Thus, a C-B amplifier has better high frequency response.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Small signal amplifiers are relatively linear because they use a small linear section of the transistor characteristics.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.Transistor packages are made of glass, metal, ceramic, or plastic.^ SOT-23 Package Plastic Encapsulate NPN Transistor s with VEBO= 7V Emitter-base Voltage .
  • Transistor Manufacturers & Suppliers 19 September 2009 23:26 UTC www.globalsources.com [Source type: FILTERED WITH BAYES]

^ SOT-23 Package Plastic Encapsulate NPN Transistor s with VEBO= 5V Emitter Base Voltage .
  • Transistor Manufacturers & Suppliers 19 September 2009 23:26 UTC www.globalsources.com [Source type: FILTERED WITH BAYES]

^ The the semiconductor die in the TO-220 and TO-247 plastic packages is mounted to a heat conductive metal slug which transfers heat from the back of the package to a metal heatsink , not shown.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.The package often dictates the power rating and frequency characteristics.^ The datasheet ratings for the power packages are only valid when mounted to a heatsink.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.Power transistors have larger packages that can be clamped to heat sinks for enhanced cooling.^ Larger packages dissipate more power.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ BD278A • NPN 100v power transistor in TO-220 plastic package.
  • Signals UK - Electronic Components and Spares Distributors. - Transistor 15 January 2010 9:09 UTC www.signalsuk.com [Source type: General]

^ I think I read the > transistor on the huge heat sink or something else...
  • Jurassic Park - No 5V, Left Sling "Held" and Blowing F5 - rec.games.pinball | Google Groups 15 January 2010 9:09 UTC groups.google.com [Source type: FILTERED WITH BAYES]

.Additionally, most power transistors have the collector or drain physically connected to the metal can/metal plate.^ Most power transistors are rated at half or less than the listed wattage.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Because the transistor is not conducting most of the time, power efficiencies are high for a class C amplifier.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ The solenoid when energized is supposed to pull in a hinged metal plate connected to the spring.
  • TECH: BSD left gate solenoid not working - rec.games.pinball | Google Groups 15 January 2010 9:09 UTC groups.google.com [Source type: FILTERED WITH BAYES]

.At the other extreme, some surface-mount microwave transistors are as small as grains of sand.^ Since transistors are more complex than some of the other components you're used to seeing at this point, these tend to have more kinds of ratings.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Intel Pentium's transistors switch at 500 megahertz or some small multiple thereabouts.
  • Transistor Story. How did we get it ? 15 January 2010 9:09 UTC www.phils.com.au [Source type: Original source]

^ V EB , the maximum reverse voltage from emitter to base is approximately 7 V for some small signal transistors.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.Often a given transistor type is available in sundry packages.^ These first devices were germanium, and represented both of the major types of transistors available worldwide at the time junction and point contact.
  • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

^ Note that the pin-outs of plastic transistors can vary within a single package type, e.g.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Package type is primarily dependent upon the required power dissipation of the transistor, much like resistors: the greater the maximum power dissipation, the larger the device has to be to stay cool.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

.Transistor packages are mainly standardized, but the assignment of a transistor's functions to the terminals is not: other transistor types can assign other functions to the package's terminals.^ In other words, two types of charge carriers -- electrons and holes -- comprise this main current through the transistor.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Note that the pin-outs of plastic transistors can vary within a single package type, e.g.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Only six other transistor types were offered.

.Even for the same transistor type the terminal assignment can vary (normally indicated by a suffix letter to the part number, q.e.^ Noise figure varies with the transistor type (part number).
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ The letter is always N. The serial number runs from 100 to 9999 indicating its development date.

^ The only way to be sure which lead is which is by a meter check, or by referencing the manufacturer's “data sheet” documentation on that particular part number of transistor.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

BC212L and BC212K).

See also

References

  1. ^ Lilienfeld, Julius Edgar, "Method and apparatus for controlling electric current" U.S. Patent 1,745,175 1930-01-28 (filed in Canada 1925-10-22, in US 1926-10-08).
  2. ^ Heil, Oskar, "Improvements in or relating to electrical amplifiers and other control arrangements and devices", Patent No. GB439457, European Patent Office, filed in Great Britain 1934-03-02, published 1935-12-06 (originally filed in Germany 1934-03-02).
  3. ^ David Bodanis (2005). Electric Universe. Crown Publishers, New York. ISBN 0-7394-5670-9. 
  4. ^ Arns, Robert G. (October 1998). "The other transistor: early history of the metal-oxide-semiconducor field-effect transistor". Engineering Science and Education Journal 7 (5): 233–240. doi:10.1049/esej:19980509. ISSN 0963-7346. http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=730824. 
  5. ^ J. Chelikowski, "Introduction: Silicon in all its Forms", Silicon: evolution and future of a technology (Editors: P. Siffert, E. F. Krimmel), p.1, Springer, 2004 ISBN 3540405461.
  6. ^ Grant McFarland, Microprocessor design: a practical guide from design planning to manufacturing, p.10, McGraw-Hill Professional, 2006 ISBN 0071459510.
  7. ^ W. Heywang, K. H. Zaininger, "Silicon: The Semiconductor Material", Silicon: evolution and future of a technology (Editors: P. Siffert, E. F. Krimmel), p.36, Springer, 2004 ISBN 3540405461.
  8. ^ Robert W. Price (2004). Roadmap to Entrepreneurial Success. AMACOM Div American Mgmt Assn. p. 42. ISBN 9780814471906. http://books.google.com/books?id=q7UzNoWdGAkC&pg=PA42&dq=transistor+inventions-of-the-twentieth-century. 
  9. ^ FETs/MOSFETs: Smaller apps push up surface-mount supply
  10. ^ Intel Multi-Core Processor Architecture Development. Retrieved December 19, 2008
  11. ^ Turley, J. (December 18, 2002).The Two Percent Solution. Embedded.com.
  12. ^ apart from a small value due to leakage currents
  13. ^ "Transistor Example". http://www.bcae1.com/transres.htm.  071003 bcae1.com
  14. ^ a b Streetman, Ben (1992). Solid State Electronic Devices. Englewood Cliffs, NJ: Prentice-Hall. pp. 301–305. ISBN 0-13-822023-9. 
  15. ^ Horowitz, Paul; Winfield Hill (1989). The Art of Electronics (2nd ed.). Cambridge University Press. pp. 115. ISBN 0-521-37095-7. 
  16. ^ W. M. C. Sansen (2006). Analog design essentials. New York ; Berlin: Springer. p. §0152, p. 28. ISBN 0-387-25746-2. http://worldcat.org/isbn/0387257462. 
  17. ^ IGBT Module 5SNA 2400E170100
  18. ^ Single Electron Transistors
  19. ^ Clive TEC Transistors Japanese Industrial Standards
  20. ^ http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv010.cgi?read=27258 Richard Freeman's HP Part numbers Crossreference
  21. ^ http://www.arrl.org/qexfiles/300-hpxref.pdf ARRL Transistor - Diode Cross Reference - H.P. Part Numbers to JEDEC (pdf)
  22. ^ http://www.qsl.net/g8yoa/cv_table.html CV Device Cross-reference by Andy Lake
  23. ^ A.S. Sedra and K.C. Smith (2004). Microelectronic circuits (Fifth ed.). New York: Oxford University Press. pp. 397 and Figure 5.17. ISBN 0-19-514251-9. 

Further reading

External links

.
  • The Transistor Educational content from Nobelprize.org
  • BBC: Building the digital age photo history of transistors
  • Transistor Flow Control — Scientific American Magazine (October 2005)
  • The Bell Systems Memorial on Transistors
  • IEEE Global History Network, The Transistor and Portable Electronics.^ Terrific site dedicated to Bell System history, including transistors.
    • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

    ^ A relatively small flow of electrons sent through the base of the transistor has the ability to exert control over a much larger flow of electrons through the collector.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ For the sake of illustration, let's insert a transistor in place of the switch to show how it can control the flow of electrons through the lamp.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    .All about the history of transistors and integrated circuits.
  • Transistorized.^ Having said all this, it must be mentioned that it is possible to use direct coupling within a multi-stage transistor amplifier circuit.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ Youll learn all the details about the design and development of this unique IC in the Hans Camenzind Oral History.
    • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

    ^ Transistor inputs to analog integrated circuits also have a V EB rating, which if exceeded will cause damage, no zenering of the inputs is allowed.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    .Historical and technical information from the Public Broadcasting Service
  • This Month in Physics History: November 17 to December 23, 1947: Invention of the First Transistor.^ That is the history of the transistor at AT&T prior to 1948, other than claiming it was invented in December of 1947 by Dr Shockley.
    • Transistor Story. How did we get it ? 15 January 2010 9:09 UTC www.phils.com.au [Source type: Original source]

    .From the American Physical Society
  • 50 Years of the Transistor.^ Professor H. C. Lins Contributions to the Field of Semiconductors Span 50 Years, Beginning with Transistor Applications Circuit Development at RCA in 1950.
    • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

    ^ An Audio Amplifier Designed by Gerry Friton Using 50 Year Old Point Contact Transistors!
    • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

    .From Science Friday, December 12, 1997
  • Bob's Virtual Transistor Museum & History.^ Transistor Museum Construction Projects Point Contact Germanium Western Electric Vintage Historic Semiconductors Photos Alloy Junction Oral History .
    • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

    ^ This Oral History provides an detailed look at Bobs impressive contributions to early transistor history at RCA, including point contact transistor research and early germanium power transistor development.
    • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

    ^ Bob McGarrahs website is indispensable for those interested in early transistor history.
    • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

    .Treasure trove of transistor history
  • Jerry Russell's Transistor Cross Reference Database.
  • The DatasheetArchive.^ Transistor Specifications http://www.sound.au.com/trans.htm Transistor Cross Reference Database Transistor Cross Reference Database.

    ^ Tektronix P/N to Generic Transistor Type Cross Reference .

    ^ NTE Transistor Cross Reference: Click HERE NTE Electronics Cross Reference Search NTE Cross Reference NTE Capacitors NTE Resistor NTE Price Search NTE Master Price List NTE Data Sheet NTE LED Flashlights .

    .Searchable database of transistor specifications and datasheets.
  • Charts showing many characteristics and giving direct access to most datasheets for 2N, 2SA, 2SB.^ If this were true, the transistor wouldn't regulate collector current at all like the characteristic curves show.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ To illustrate this graphically, a “load line” is sometimes plotted over a transistor's characteristic curves to illustrate its range of operation while connected to a load resistance of specific value shown in Figure below .
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    2SC, 2SD, 2SH-K, and other numbers.
  • http://userpages.wittenberg.edu/bshelburne/Comp150/LogicGatesCircuits.html
  • A short video showing how a transistor works.

Datasheets

.A wide range of transistors has been available since the 1960s and manufacturers continually introduce improved types.^ These first devices were germanium, and represented both of the major types of transistors available worldwide at the time junction and point contact.
  • Transistor Museum Construction Projects Point Contact Germanium WesternElectric Vintage Historic Semiconductors Photos Alloy Junction Oral History 15 January 2010 9:09 UTC semiconductormuseum.com [Source type: FILTERED WITH BAYES]

^ As such, manufacturers provide a set of β (or “h fe ”) figures for a given transistor over a wide range of operating conditions, usually in the form of maximum/minimum/typical ratings.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Since this 0.7 volt difference is fairly constant over a wide range of load currents, a zener diode with a 0.7 volt higher rating can be chosen for the application.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

A few examples from the main families are noted below. Unless otherwise stated, all types are made from silicon semiconductor. .Complementary pairs are shown as NPN/PNP or N/P channel.^ An NPN transistor is modeled in the figure shown, but a PNP transistor would be only slightly different (only the base-emitter diode would be reversed).
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Transistors Q 3 and Q 4 are known as a complementary pair because these NPN and PNP transistors amplify alternate halves (positive and negative, respectively) of the waveform.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

Links go to manufacturer datasheets, which are in PDF format. (On some datasheets the accuracy of the stated transistor category is a matter of debate.)
  • 2N3904/2N3906, BC182/BC212 and BC546/BC556: Ubiquitous, BJT, general-purpose, low-power, complementary pairs. .They have plastic cases and cost roughly ten cents US in small quantities, making them popular with hobbyists.
  • AF107: Germanium, 0.5-watt, 250 MHz PNP BJT.
  • BFP183: Low power, 8 GHz microwave NPN BJT.
  • LM394: "supermatch pair", with two NPN BJTs on a single substrate.
  • 2N2219A/2N2905A: BJT, general purpose, medium power, complementary pair.^ Small-signal/general-purpose transistors .
    • Transistor Manufacturers & Suppliers 19 September 2009 23:26 UTC www.globalsources.com [Source type: FILTERED WITH BAYES]

    ^ See also: Zener diodes , Rectifiers , Thyristors/thyristor modules , FETs/MOSFETs , Small-signal/general-purpose transistors .
    • Transistor Manufacturers & Suppliers 19 September 2009 23:26 UTC www.globalsources.com [Source type: FILTERED WITH BAYES]

    ^ The moderate output impedance of the common-emitter configuration helps make it a popular choice for general use.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    .With metal cases they are rated at about one watt.
  • 2N3055/MJ2955: For years, the venerable NPN 2N3055 has been the "standard" power transistor.^ Most power transistors are rated at half or less than the listed wattage.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ If the transistor is not saturated, and in fact is dropping substantial voltage between collector and emitter, the maximum power dissipation rating will probably be exceeded before the maximum collector current rating.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ NPN Transistor with 300mW Collector Power Dissipation .

    Its complement, the PNP MJ2955 arrived later. .These 1 MHz, 15A, 60V, 115W BJTs are used in audio power amplifiers, power supplies, and control.
  • 2N7000 is a typical small-signal field-effect transistor.
  • 2SC3281/2SA1302: Made by Toshiba, these BJTs have low-distortion characteristics and are used in high-power audio amplifiers.^ Field Effect Transistor 900v 8a .
    • Signals UK - Electronic Components and Spares Distributors. - Transistor 15 January 2010 9:09 UTC www.signalsuk.com [Source type: General]

    ^ So far, we've seen the transistor used as an amplifier for DC signals.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ An ideal transistor would show 0% distortion in amplifying a signal.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    .They have been widely counterfeited[1].
  • BU508: NPN, 1500 V power BJT. Designed for television horizontal deflection, its high voltage capability also makes it suitable for use in ignition systems.
  • MJ11012/MJ11015: 30 A, 120 V, 200 W, high power Darlington complementary pair BJTs.^ An NPN darlington pair.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ Complementary pairs of transistors running in class B operation are often used to deliver high power amplification in audio signal systems, each transistor of the pair handling a separate half of the waveform cycle.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ A typical value for a small signal transistor is 60 to 80 V. In power transistors, this could range to 1000 V, for example, a horizontal deflection transistor in a cathode ray tube display.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    .Used in audio amplifiers, control, and power switching.
  • 2N5457/2N5460: JFET (depletion mode), general purpose, low power, complementary pair.
  • BSP296/BSP171: IGFET (enhancement mode), medium power, near complementary pair.^ For the complete circuit see“ Direct coupled complementary symmetry 3 w audio amplifier,” Ch 9 .
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ An example of an audio amplifier stage using base-biasing is “Crystal radio with one transistor .
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ This is not acceptable in a power amplifier if we expect the collector voltage to swing from near V CC to near ground.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    .Used for logic level conversion and driving power transistors in amplifiers.
  • IRF3710/IRF5210: IGFET (enhancement mode), 40A, 100V, 200W, near complementary pair.^ Direct coupled complementary-pair amplifier replaces transformers with transistors.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ This is not the only way in which a transistor may be used as an amplifier, as we will see in later sections of this chapter.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    ^ The cure for shifting V BE is a pair of transistors configured as a differential amplifier.
    • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

    For high-power amplifiers and power switches, especially in automobiles.

Patents


Study guide

Up to date as of January 14, 2010

From Wikiversity

Crystal Clear app kaddressbook.png
Please help develop this page
This page was created, but so far, little content has been added. Everyone is invited to help expand and create educational content for Wikiversity. .If you need help learning how to add content, see the editing tutorial and the MediaWiki syntax reference.^ Help when you need it: T8 Service .
  • Transistor 8 | IT Services for Business 15 January 2010 9:09 UTC transistor8.com [Source type: General]

^ Learn how you can be part of the show .
  • Transistor Love Story Movie Reviews, Pictures - Rotten Tomatoes 15 January 2010 9:09 UTC www.rottentomatoes.com [Source type: FILTERED WITH BAYES]

^ In order to grasp the transistor effect, you need to understand how a transistor can function both as an insulator and a conductor.
  • Transistor History - Invention of the Transistor 19 September 2009 23:26 UTC www.ideafinder.com [Source type: FILTERED WITH BAYES]

.Please do not simply copy-and-paste large chunks from other projects.^ Close Please copy/paste the following text to properly cite this HowStuffWorks article: "Transistor."

Merge-arrows.svg
A merger has been proposed.
.It has been suggested that this resource or section be merged with Transistors (Discuss).^ This mode, as discussed in section 5.3.1 , is the one used in bipolar transistor amplifiers.
  • Bipolar Junction Transistors 15 January 2010 9:09 UTC ece-www.colorado.edu [Source type: Reference]

^ Tags : Semiconductors , transistor flaw , transistor , chip design , NIST , chip Discussion threads 2009-05-29 Additional Resources .
  • transistor flaw Resources | ZDNet 15 January 2010 9:09 UTC updates.zdnet.com [Source type: General]

.Transistor is a two junction device.^ There are two kinds, the bipolar transistor (also called the junction transistor), and the field effect transistor (FET).
  • Definition of TRANSISTOR (Meaning of TRANSISTOR), a 10 Letter Word 15 January 2010 9:09 UTC www.hyperdictionary.com [Source type: Reference]

^ There are basically two types, the bipolar transistor (also called the junction transistor), and the field effect transistor (FET).
  • Sweetwater inSync 15 January 2010 9:09 UTC www.sweetwater.com [Source type: FILTERED WITH BAYES]
  • Glossary: Transistor | Sweetwater.com 15 January 2010 9:09 UTC www.sweetwater.com [Source type: FILTERED WITH BAYES]

^ Some circuits are designed to use the transistor as a switching device; current in the base-emitter junction creates a low-resistance path between the collector and emitter.
  • transistor Facts, information, pictures | Encyclopedia.com articles about transistor 15 January 2010 9:09 UTC www.encyclopedia.com [Source type: FILTERED WITH BAYES]
  • Transistor 15 January 2010 9:09 UTC www.mtmi.vu.lt [Source type: FILTERED WITH BAYES]
  • http://www.factmonster.com/ce6/sci/A0861609.html 19 September 2009 23:26 UTC www.factmonster.com [Source type: Reference]

Formed by joinning two semi-conducting material , one is positive nature denoted by capital P , one is negative in nature denoted by N in the arrangement like below
.1) PNP , one negative semi-conductor (usually Si) in between two positive semi-conductor (usually Ge) .^ A transistor with one layer of positively charged semiconductor material between two negatively charged layers.
  • Questions about NPN Transistor - Ask.com 15 January 2010 9:09 UTC www.ask.com [Source type: General]

^ (Two other commonly used names for Shockley's creation are the positive-negative-positive or pnp transistor, and the bipolar transistor.
  • The Chip Collection - STATE OF THE ART - Smithsonian Institution 15 January 2010 9:09 UTC smithsonianchips.si.edu [Source type: FILTERED WITH BAYES]

^ Consider the base-emitter PN junction that the input signal is sent to: it can only conduct in one direction (base positive and emitter negative).
  • Bipolar transistor biasing circuits : Worksheet 15 January 2010 9:09 UTC www.allaboutcircuits.com [Source type: FILTERED WITH BAYES]

This kind of arrangement is called PNP Transistor
о--[P|N|P]--о
.2) NPN , one positive semi-conductor (usually Ge) in between two nagative semi-conductor (usually Si) .^ Equivalent to two diodes connected back-to-back NPN Transistor : one P-Typed Semi-Conductor between 2 N-Typed Semi-Conductor .
  • Transistor – Wikibooks tiếng Việt 15 January 2010 9:09 UTC vi.wikibooks.org [Source type: Academic]

^ A transistor usually comes in one of two different configurations, NPN or PNP.  The basic function of a transistor is to amplify current through a circuit.
  • How to test a transistor | OhmCheck.com 15 January 2010 9:09 UTC www.ohmcheck.com [Source type: FILTERED WITH BAYES]

^ If both give a reading, then the positive meter lead is connected to the base, and the transistor is NPN. Try the positive meter lead on all three transistor leads until the other two leads give readings.
  • Allen's Halloween Page: Allen's Wet Finger Transistor Test 15 January 2010 9:09 UTC softlyspokenmagicspells.com [Source type: General]

This kind of arrangement is called NPN Transistor
о--[N|P|N]--о
.With the right connection, by connecting transistor with resistor(s) Transistor can acts as an amplifier, a switch, a buffer.^ A transistor can work as an amplifier as well as a switch.

^ A tool that can be used as an Amplifier, a Buffer, or a Switch .
  • Transistor – Wikibooks tiếng Việt 15 January 2010 9:09 UTC vi.wikibooks.org [Source type: Academic]

^ Transistor Amplifier Transistor Buffer Transistor Switch [ sửa ] Mạch Điện .
  • Transistor – Wikibooks tiếng Việt 15 January 2010 9:09 UTC vi.wikibooks.org [Source type: Academic]

.A transistor has three terminals namely, emitter, base and collector.^ The three layers of the transistors are named the emitter, the base and the collector.

^ Alternatively, the transistor can be a pnp transistor with the collector and emitter being p doped and the base being n doped.
  • TRANSISTOR - Patent application - heterojunction bipolar transistor comprising a substrate 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

^ The transistor can be an npn transistor with the collector and emitter being n doped and the base being p doped.
  • TRANSISTOR - Patent application - heterojunction bipolar transistor comprising a substrate 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

.Emitter is the region thru which majority carriers enter the transistor.^ Instead, they drift through the base-collector depletion region and end up as majority carriers in the collector region.
  • Bipolar Junction Transistors 15 January 2010 9:09 UTC ece-www.colorado.edu [Source type: Reference]

^ Therefore, from this point on, only the schematic symbol for the transistor will be used in the illustrations, and rather than thinking about majority and minority carriers, we will now start thinking in terms of emitter, base, and collector current.
  • The basic transistor amplifier 15 January 2010 9:09 UTC www.tpub.com [Source type: Reference]

^ The MOSFET transistor has three major regions (modes) of operation: cutoff, saturation and non-saturated region.
  • Transistor Level Implementation of CMOS Combinational Logic Circuits 15 January 2010 9:09 UTC et.nmsu.edu [Source type: Reference]

.Emitter is heavily doped.^ The emitter is heavily doped; its job is to emit or inject electrons into the base.

.Base is the middle layer and it is very lightly doped.^ The middle layer is the base.
  • How does a transistor work? 15 January 2010 9:09 UTC www.physlink.com [Source type: Reference]

^ A multilayer semiconductor wafer as claimed in claim 25, wherein the collector and emitter layers are p doped and the base layer is n doped.
  • TRANSISTOR - Patent application - heterojunction bipolar transistor comprising a substrate 15 January 2010 9:09 UTC www.faqs.org [Source type: Reference]

^ The emitter-base PN junction has a slightly greater forward voltage drop than the collector-base PN junction, because of heavier doping of the emitter semiconductor layer.
  • Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 4 15 January 2010 9:09 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]
  • Meter check of a transistor : BIPOLAR JUNCTION TRANSISTORS 19 September 2009 23:26 UTC www.allaboutcircuits.com [Source type: FILTERED WITH BAYES]

Collector is wide and moderately doped.
Wikipedia-logo.png Run a search on Transistor at Wikipedia.

Wiktionary

Up to date as of January 14, 2010

Definition from Wiktionary, a free dictionary

German

Noun

Transistor m. (genitive Transistors, plural Transistoren)
  1. transistor

Simple English

A transistor is an electronic component that can be used as an amplifier, or as a switch. They are found in all but the most simple electronic devices. A transistor has three connectors or terminals: the emitter, the base, and the collector. The current goes from the emitter, hence the word emit, and goes to the collector, since it collects, depending on the current from the base. The transistor can be used for a variety of different things including amplifiers and digital switches for computer microprocessors.

Transistors have almost totally replaced vacuum tubes in the majority of applications such as home audio equipment, and televisions.

Other websites


Citable sentences

Up to date as of December 24, 2010

Here are sentences from other pages on Transistor, which are similar to those in the above article.








Got something to say? Make a comment.
Your name
Your email address
Message