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see transistortransistor,
three-terminal, solid-state electronic device used for amplification and switching. It is the solid-state analog to the triode electron tube; the transistor has replaced the electron tube for virtually all common applications.
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McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


(Field Effect Transistor) One of two major categories of transistor; the other is bipolar. FETs use a gate element that, when charged, creates an electromagnetic field that changes the conductivity of a silicon channel and turns the transistor on or off. FETs are fabricated as individually packaged discrete components as well as by the hundreds of millions on a single chip.

FETs vs. Bipolar
FET-based silcon chips are easier to construct than their bipolar counterparts. FETs switch a little slower than bipolar transistors, but use less power. Once the gate terminal on an FET has been charged, no more current is needed to keep that transistor on (closed) for the duration of time required. By comparison, a bipolar transistor requires a small amount of current flowing to keep the transistor on. While the current for one transistor may be negligible, it adds up when millions are switching simultaneously. The heat dissipated on bipolar limits the total number of transistors that can be built on the chip, which is why CMOS logic (based on FETs) is used to build chips with millions of transistors.

The most widely used and widely known FETs are MOSFETs (metal oxide semiconductor FETs), which come in NMOS (n-channel) and PMOS (p-channel) varieties. On a chip, NMOS and PMOS transistors are wired together in a complementary fashion to create CMOS logic, which is the most predominant and used in almost every electronic device today. See MOSFET and n-type silicon.

There Are Many Kinds of FETs
Similar to MOSFETs are JFETs (junction FETs), which use a PN junction gate rather than a poly-crystalline gate. Used for microwave communications, MESFETs (metal semiconductor FETs) are similar to JFETs, but use a Schottky metal gate and are made from gallium arsenide or indium phosphide, not silicon. Evolving from MESFETs for higher-frequency applications are HEMTs and PHEMTs (high electron mobility transistors and pseudomorphic high electron mobility transistors). HEMTs are also called MODFETs, TEGFETs and SDHTs (modulation doped FETs, two-dimensional electron gas FETs and selectively doped heterojunction transistors).

Another high-frequency FET is the gallium arsenide-based CHFET (complementary heterostructure FET), which uses a complementary architecture similar to CMOS.

FETs vs. Bipolar
After the gate is charged in an FET, no more current flows, but the transistor remains closed (turned on) during the required time period. Bipolar transistors (BJTs) require current the entire time the transistor must be closed.
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References in periodicals archive ?
Samples of the Si875x isolated FET drivers are available now with production quantities planned for November 2016.
Beginning with the mid-1970s, Fet closely followed the events which took place in Poland.
Combination of Fet A + PA Only Partly Lost the Effect on Expressions of AGT and [AT.sub.1]R in the 3T3-L1 Adipocytes When Blocking NF-[kappa]B Beforehand.
With a single, convergent system that can support huge volumes of real-time prepaid and postpaid events generated from any service, whether mobile, fixed-line or broadband, and on low-cost hardware, FET will be able to reduce operational and hardware costs and cost-efficiently scale the system to support growing data usage and subscriber numbers, as well as additional lines of business, said Rebecca Prudhomme, vice president of product and solutions marketing at Amdocs.
On the other hand, when using FET switches, separate control lines are required.
Coperion has tested the all three system setup variations on the FET. The downstream configuration (FET insert placed in the main extruder barrel section downstream of the main feed location) was evaluated for an HDPE powder resin This was first run in the lab, and the system then was installed on a ZSK 240 production unit.
The United States of America (2) renewed the unsettled discussion surrounding the fair and equitable treatment (FET) standard in investment treaty arbitration.
"The reorganisation of Rostelecom is expected to involve the merger of all seven Russian regional telecoms operators (including FET) into the group in Q1 2011.
The FET system has reportedly proven itself on many new Coperion machines since its market launch.
[USPRwire, Mon Aug 19 2019] Market Research Hub (MRH) has actively included a new research study titled "Global (United States, European Union and China) Gate-All-Around FET (GAAFET) Technology Market Research Report 2019-2025" to its wide online repository.
Mae'r fet Kate O'Sullivan yn esbonio'r sefyllfa: "Ro'n ni'n becso mai rhyw fath o 'bleeding disorder' oedd gan Frankie a chododd y cwestiwn bod Frankie, efallai, wedi llyncu gwenwyn llygod mawr."