Editing Transistor (section)

===Classification===
{{more citations needed|section|date=December 2020}}
<!-- START OF THE SYMBOLS -->
{{float_begin|side=right}}
|- style="text-align:center;"
|[[File:BJT PNP symbol.svg|80px]]||PNP||[[File:JFET P-Channel Labelled.svg|80px]]||P-channel
|- style="text-align:center;"
|[[File:BJT NPN symbol.svg|80px]]||NPN||[[File:JFET N-Channel Labelled.svg|80px]]||N-channel
|- style="text-align:center;"
|BJT||||JFET||
{{float_end|caption=BJT and JFET symbols}}

[[File:IGBT symbol.svg|thumb|right|Insulated-gate bipolar transistor (IGBT)]]

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|- style="text-align:center;"
|[[File:IGFET P-Ch Enh Labelled.svg|80px]]||[[File:IGFET P-Ch Enh Labelled simplified.svg|80px]]||[[File:IGFET P-Ch Dep Labelled.svg|80px]]||P-channel
|- style="text-align:center;"
|[[File:IGFET N-Ch Enh Labelled.svg|80px]]||[[File:IGFET N-Ch Enh Labelled simplified.svg|80px]]||[[File:IGFET N-Ch Dep Labelled.svg|80px]]||N-channel
|- style="text-align:center;"
|colspan="2"|MOSFET enh||MOSFET dep||
{{float_end|caption=MOSFET symbols}}
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Transistors are categorized by
* Structure: [[MOSFET]] (IGFET), [[Bipolar junction transistor|BJT]], [[JFET]], [[insulated-gate bipolar transistor]] (IGBT), other type.{{which|date=April 2021}}.
* Semiconductor material ([[dopant]]s): 
** The [[metalloids]]; [[germanium]] (first used in 1947) and [[silicon]] (first used in 1954)—in [[Amorphous silicon|amorphous]], [[Polycrystalline silicon|polycrystalline]] and [[Monocrystalline silicon|monocrystalline]] form.
** The compounds [[gallium arsenide]] (1966) and [[silicon carbide]] (1997).
** The [[alloy]] [[silicon–germanium]] (1989) 
** The [[allotrope of carbon]] [[Graphene#Electronics|graphene]] (research ongoing since 2004), etc. (see [[#Semiconductor material|Semiconductor material]]).
* [[Electrical polarity]] (positive and negative): [[NPN transistor|NPN]], [[PNP transistor|PNP]] (BJTs), N-channel, P-channel (FETs).
* Maximum [[power rating]]: low, medium, high.
* Maximum operating frequency: low, medium, high, [[radio frequency|radio]] (RF), [[microwave]] frequency (the maximum effective frequency of a transistor in a common-emitter or common-source circuit is denoted by the term {{math|''f''<sub>''T''</sub>}}, an abbreviation for [[gain–bandwidth product#Transistors|transition frequency]]—the frequency at which the transistor yields unity voltage gain)
* Application: switch, general purpose, audio, [[high voltage]], super-beta, matched pair.
* Physical packaging: [[through-hole technology|through-hole]] metal, through-hole plastic, [[Surface-mount technology|surface mount]], [[ball grid array]], power modules (see [[#Packaging|Packaging]]).
* Amplification factor [[Transistor models|{{math|''h''<sub>''FE''</sub>}}]], {{math|''β''<sub>''F''</sub>}} ([[transistor beta]])<ref>{{cite web|title=Transistor Example|url=http://www.bcae1.com/transres.htm|url-status=live|archive-url=https://web.archive.org/web/20080208150020/http://www.bcae1.com/transres.htm|archive-date=February 8, 2008}} 071003 bcae1.com</ref> or {{math|''g''<sub>''m''</sub>}} ([[transconductance]]).
* Working temperature: Extreme temperature transistors and traditional temperature transistors ({{convert|−55|to|150|C|F}}). Extreme temperature transistors include high-temperature transistors (above {{convert|150|C|F}}) and low-temperature transistors (below {{convert|-55|C|F}}). The high-temperature transistors that operate thermally stable up to {{convert|250|C|F}} can be developed by a general strategy of blending interpenetrating semi-crystalline conjugated polymers and high glass-transition temperature insulating polymers.<ref>{{Cite journal|last1=Gumyusenge|first1=Aristide|last2=Tran|first2=Dung T.|last3=Luo|first3=Xuyi|last4=Pitch|first4=Gregory M.|last5=Zhao|first5=Yan|last6=Jenkins|first6=Kaelon A.|last7=Dunn|first7=Tim J.|last8=Ayzner|first8=Alexander L.|last9=Savoie|first9=Brett M.|last10=Mei|first10=Jianguo|date=December 7, 2018|title=Semiconducting polymer blends that exhibit stable charge transport at high temperatures|journal=Science|language=en|volume=362|issue=6419|pages=1131–1134|doi=10.1126/science.aau0759|pmid=30523104|issn=0036-8075|bibcode=2018Sci...362.1131G|doi-access=free}}</ref>

Hence, a particular transistor may be described as ''silicon, surface-mount, BJT, NPN, low-power, high-frequency switch''.