View source for 2N2222 NPN bipolar junction transistor

[[Image:2N2222_data.png|left]]
[[Image:2N2222A.jpg|thumb|200px|2N2222A with Emitter, Base and Collector identified as "e" "b" "c" respectively.]]

The '''2N2222''' is a common [[NPN transistor|NPN]] [[bipolar junction transistor]]  used for general purpose low-power [[amplifier|amplifying]] or switching applications. It is designed for low to medium [[electric current|current]], low [[electric power|power]], medium [[voltage]], and can operate at moderately high speeds.  It is  made in the [[TO-18]] metal can as shown in the picture. Replacements are commonly available now in the cheaper [[TO-92]] packaging, where it is known as the PN2222 or P2N2222, which has similar specifications except for the lower maximum collector current.<ref>http://www.fairchildsemi.com/ds/PN/PN2222.pdf Retrieved 3rd June 2012 </ref>

The 2N2222 is considered a very common transistor,<ref>Dan O'Sullivan, Tom Igoe; "Physical Computing"; Cengage Learning; pp.19; 2004; ISBN 1-59200-346-X</ref><ref>Brad Graham, Kathy McGowan; "Mind Performance Projects for the Evil Genius"; McGraw Hill Professional; pp.18; 2010; ISBN 978-0-07-162392-6</ref><ref>Brad Graham, Kathy McGowan; "51 High-Tech Practical Jokes for the Evil Genius"; McGraw Hill Professional; pp.12; 2007; ISBN 978-0-07-149494-6</ref> and is used as an exemplar of an NPN transistor. It is frequently used as a small-signal transistor,<ref>Gordon McComb; "The Robot Builder's Bonanza"; McGraw-Hill Professional; 2001; pp.261; ISBN 978-0-07-136296-2</ref><ref>William Rynone; "Linear Active Circuits &mdash; Design and Analysis"; Artech House; pp.19; 1986; ISBN 0-89006-199-8</ref> and it remains a small general purpose transistor<ref>Dennis Barnaal, "Analog and Digital Electronics for Scientific Application"; Breton Publishers; pp.301; 1982; ISBN 0-534-01044-X</ref> of enduring popularity.<ref>
{{cite book
 | title = Build your own low-power transmitters: projects for the electronics experimenter
 | author = Rudolf F. Graf and William Sheets
 | publisher = Newnes
 | year = 2001
 | isbn = 978-0-7506-7244-3
 | page = 14
 | url = http://books.google.com/books?id=70rYm4s-9lcC&pg=PA14
 | quote = The 2N2222, 2N2905, and 2N3055 devices, for example, which date back to the 1960s but have been improved, are still useful in new designs and are still popular for experimenters.
 }}</ref><ref>
{{cite book
 | title = High frequency and microwave engineering
 | author = Ed Da Silva
 | publisher = Newnes
 | year = 2001
 | isbn = 978-0-7506-5046-5
 | page = 263
 | url = http://books.google.com/books?id=eloRn9yF3XoC&pg=PA263
 | quote = Typical examples are the well known NPN and PNP industrial and military types, 2N2222 and 2N2907, which have been used for over four decades and are still being used in many designs.
 }}</ref><ref>
{{cite web
 | title = THE DEVELOPMENT OF THE 2N2222: The Most Successful and Widely Used Transistor Ever Developed!
 | url =  http://semiconductormuseum.com/Museum_Index.htm
 | work = The Transistor Museum
 | author = Jack Ward
 | accessdate = 26 March 2011
 | quote = Since its initial product launch by Motorola at the 1962 IRE Convention, the 2N2222 has become the most widely used and universally recognized transistor of all time.  Billions of units have been manufactured over the past 45 years and there is continuing high volume annual production. 
 | archiveurl= http://web.archive.org/web/20110414154610/http://semiconductormuseum.com/Museum_Index.htm| archivedate= 14 April 2011 <!--DASHBot-->| deadurl= no}}</ref>

The 2N2222 was part of a family of devices described by Motorola at a 1962 [[Institute of Radio Engineers|IRE]] convention.<ref>http://www.semiconductormuseum.com/Transistors/Motorola/Haenichen/Haenichen_Page11.htm Haenichen oral history retrieved from the Semiconductor Museum 2011 May 13</ref> Since then it has been made by many semiconductor companies, for example, [[Texas Instruments]].<ref name=TIData>''The Transistor and Diode Data Book for Design Engineers'', Texas Instruments Incorporated, no date, TI publication number CC413 71242-73-CSS, page 4-93</ref>

==Specifications==
The [[JEDEC]] registration of a device number ensures particular rated values will be met by all parts offered under that number. JEDEC registered parameters include outline dimensions, small-signal current [[gain]], [[Gain–bandwidth product#Transistors|transition frequency]], maximum values for voltage withstand, current rating, power dissipation and temperature rating, and others, measured under standard test conditions.  Other part numbers will have different parameters. The exact specs depend on the manufacture case type and variation. Therefore it is important to reference the datasheet for the exact part number and manufacturer.
{|class="wikitable"
|-
!Manufacturer
!V<sub>ce</sub>
!I<sub>c</sub>
!P<sub>D</sub>
!f<sub>T</sub>
|-
!ST Microelectronics<ref>http://www.st.com/stonline/products/literature/ds/9288/2n2222a.pdf Datasheet accessed 6/19/2009</ref><br>2N2222A
|40 V
|800 mA
|500&nbsp;mW/1.8 W
|300&nbsp;MHz
|}
All variations have a [[Bipolar_junction_transistor#Transistor_.27alpha.27_and_.27beta.27|beta]] or current gain (hFE) of at least 100 in optimal conditions.  It is used in a variety of analog amplification and switching applications.

NPN silicon transistors with similar properties are also made in a variety of small through-hole and surface mount packages including [[TO-92]], [[SOT-23]], and [[SOT-223]].

==Related transistors==
The [[BC548]] is a low voltage, low current; general-purpose switching transistor in a TO-92 package.

The [[2N2907]] is an equally popular ([[PNP transistor|PNP]]) transistor complementary to the 2N2222.<ref>
{{cite book
 | title = Junkbots, bugbots, and bots on wheels: building simple robots with BEAM technology
 | author = Dave Hrynkiw and Mark W. Tilden
 | publisher = McGraw-Hill Professional
 | year = 2002
 | isbn = 978-0-07-222601-0
 | page = 44
 | url = http://books.google.com/books?id=vY2hd3bCQw8C&pg=PA44
 | quote = Learn to keep an eye open for the following transistors, as they're among the most useful, inexpensive, and popular types: PN2222/PN2907 These are general-purpose NPN/PNP transistors that can drive some good amounts of power. They're listed together because they're complementary transistors.
 }}</ref>

The [[2N3904]] is an NPN transistor that can only switch one-third the current of the 2N2222 but has otherwise similar characteristics.

The [[2N2219]] is very similar with higher power dissipation rating.

==Documents==
* [[File:Philips_2N2222,_2N2222A.pdf]]

==References==

{{reflist}}

== External links ==
* [http://www.fairchildsemi.com/ds/PN/PN2222.pdf Datasheet for Fairchild Semiconductor's equivalent PN2222 (PDF)]
* [http://datasheetreference.com/2n2222-datasheet.html 2N2222 Transistor History, Packaging and Datasheet]

[[Category:Electronic Component (Transistor)]]