Transistor - Revision history

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Jmdonev at 21:56, 9 May 2018

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	[[Category:Done ~~2015~~-08-21]]		[[Category:Done 2018-04-30]]
	[[File:Npn transistor.png\|200px\|thumbnail\|Figure 1.<ref>Wikimedia Commons. ''File:Diagrama de Transistor NPN.svg'' [Online]. Available: https://commons.wikimedia.org/wiki/File:Diagrama_de_Transistor_NPN.svg</ref> The schematic symbol for an NPN transistor with the collector, base, and emitter currents labeled.]]		[[File:Npn transistor.png\|200px\|thumbnail\|Figure 1.<ref>Wikimedia Commons. ''File:Diagrama de Transistor NPN.svg'' [Online]. Available: https://commons.wikimedia.org/wiki/File:Diagrama_de_Transistor_NPN.svg</ref> The schematic symbol for an NPN transistor with the collector, base, and emitter currents labeled.]]
	<onlyinclude>'''Transistors''' are [[electrical component]]s of [[circuit]]s that can act as [[amplifier]]s and as [[switch]]es. Transistors are integral to modern circuitry, with hundreds of millions of them used in modern [[integrated circuit]]s for computing.</onlyinclude> They are the basis for digital logic and computation, and they catalyzed a revolution in electronics.<ref>''How Transistors Work - Transistors and the Computer Age'' [Online]. Available: http://electronics.howstuffworks.com/transistor3.htm</ref> The most basic type of transistor is the bipolar junction transistor (see Figure 1).		<onlyinclude>'''Transistors''' are [[electrical component\|components]] of [[electric circuit]]s that can act as [[amplifier]]s and as [[switch]]es. Transistors are integral to modern circuitry, with hundreds of millions of them used in modern [[integrated circuit]]s for computing.</onlyinclude> They are the basis for digital logic and computation, and they catalyzed a revolution in electronics.<ref>''How Transistors Work - Transistors and the Computer Age'' [Online]. Available: http://electronics.howstuffworks.com/transistor3.htm</ref> The most basic type of transistor is the bipolar junction transistor (see Figure 1).

	==Types and Functions==		==Types and Functions==
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	Transistors are also widely used as amplifiers, since they take a small input current through the base to produce a larger, proportional current between the collector and emitter. Amplification plays a key role in many circuits, most obviously in microphones, loudspeakers, radios, televisions, phones, and hearing aids.<ref name = b>''Transistors - Applications II: Amplifiers'' [Online]. Available: https://learn.sparkfun.com/tutorials/transistors/applications-ii-amplifiers</ref><ref>''How Transistors Work - Transistor Radios and the Electronics Revolution'' [Online]. Available: http://electronics.howstuffworks.com/transistor2.htm</ref> Transistor amplification also allows for large current gains and complex processes like differential amplification, where the difference between two input signals is amplified.<ref name = b></ref>		Transistors are also widely used as amplifiers, since they take a small input current through the base to produce a larger, proportional current between the collector and emitter. Amplification plays a key role in many circuits, most obviously in microphones, loudspeakers, radios, televisions, phones, and hearing aids.<ref name = b>''Transistors - Applications II: Amplifiers'' [Online]. Available: https://learn.sparkfun.com/tutorials/transistors/applications-ii-amplifiers</ref><ref>''How Transistors Work - Transistor Radios and the Electronics Revolution'' [Online]. Available: http://electronics.howstuffworks.com/transistor2.htm</ref> Transistor amplification also allows for large current gains and complex processes like differential amplification, where the difference between two input signals is amplified.<ref name = b></ref>

			== For Further Reading ==
			For further information please see the related pages below:
			*[[Semiconductor]]
			*[[Metal]]
			*[[Photovoltaic cell]]
			*[[AC to DC adapter]]
			* Or explore a [[Special:Random\| random page!]]

	==References==		==References==
	{{reflist}}[[Category:Uploaded]]		{{reflist}}[[Category:Uploaded]]

J.williams: 1 revision imported

2015-08-26T21:31:55Z

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J.williams at 18:50, 24 August 2015

2015-08-24T18:50:48Z

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[[Category:Done 2015-08-21]]
[[File:Npn transistor.png|200px|thumbnail|Figure 1.<ref>Wikimedia Commons. ''File:Diagrama de Transistor NPN.svg'' [Online]. Available: https://commons.wikimedia.org/wiki/File:Diagrama_de_Transistor_NPN.svg</ref> The schematic symbol for an NPN transistor with the collector, base, and emitter currents labeled.]]
<onlyinclude>'''Transistors''' are [[electrical component]]s of [[circuit]]s that can act as [[amplifier]]s and as [[switch]]es. Transistors are integral to modern circuitry, with hundreds of millions of them used in modern [[integrated circuit]]s for computing.</onlyinclude> They are the basis for digital logic and computation, and they catalyzed a revolution in electronics.<ref>''How Transistors Work - Transistors and the Computer Age'' [Online]. Available: http://electronics.howstuffworks.com/transistor3.htm</ref> The most basic type of transistor is the bipolar junction transistor (see Figure 1).

==Types and Functions==
Bipolar junction transistors (BJT) are composed of three [[doping|doped]] [[semiconductor]]s. NPN transistors have a thin p-doped region between two n-doped sections while PNP transistors have a thin n-doped region between two p-doped sections. The only functional difference between PNP and NPN transistors is the biasing of each PN [[diode]] required for the transistor to work.<ref name = a>''Introduction to Bipolar Junction Transistors (BJT)'' [Online]. Available:http://www.allaboutcircuits.com/textbook/semiconductors/chpt-4/bipolar-junction-transistors-bjt/</ref> All three regions of the transistor have a distinct connection to the external circuit (see Figure 2). The end regions are called the collector and emitter such that [[conventional current]] flow is from collector to emitter through an NPN transistor.<ref>''Transistors'' [Online]. Available:https://learn.sparkfun.com/tutorials/transistors/operation-modes</ref>
[[File:BJT transistor.png|450px|thumbnail|Figure 2.<ref name = a></ref> a) PNP schematic b) PNP layout c) NPN schematic d) NPN layout]]
Bipolar transistors work as current regulators or electronic switches. Depending on the [[voltage]] of the small [[current]] through the base, the much larger collector-to-emitter current can be strictly controlled or shut off.

Most modern transistors are known as Metal Oxide Semiconductor Field Effect Transistors (MOSFETs), which work on the same principles as BJTs but are constructed and operated quite differently. However, both BJTs and MOSFETs have the same fundamental capability of controlling a large current with a small one.<ref>''Junction Field Effect Transistor'' [Online]. Available: http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/fet.html</ref>

For more information on how transistors work, visit [http://www.allaboutcircuits.com/textbook/semiconductors/#chpt-4 All About Circuits] and the simulation at [http://www.learnabout-electronics.org/bipolar_junction_transistors_05.php Learn About Electronics].
==Uses==
Transistors are ubiquitous in modern electronics, but the most fundamental use of a transistor is as an electronic switch. In cutoff mode, a transistor will allow no current to pass between the collector and emitter. In saturation mode, the transistor allows unrestricted current flow. These two distinct states create a binary effect that can be exploited to create logic gates, microcontrollers, microprocessors, and other [[integrated circuit]]s.<ref>''Transistors - Applications I: Switches'' [Online]. Available: https://learn.sparkfun.com/tutorials/transistors/applications-i-switches</ref> As such, the transistor is the fundamental component of all digital computing.

Transistors are also widely used as amplifiers, since they take a small input current through the base to produce a larger, proportional current between the collector and emitter. Amplification plays a key role in many circuits, most obviously in microphones, loudspeakers, radios, televisions, phones, and hearing aids.<ref name = b>''Transistors - Applications II: Amplifiers'' [Online]. Available: https://learn.sparkfun.com/tutorials/transistors/applications-ii-amplifiers</ref><ref>''How Transistors Work - Transistor Radios and the Electronics Revolution'' [Online]. Available: http://electronics.howstuffworks.com/transistor2.htm</ref> Transistor amplification also allows for large current gains and complex processes like differential amplification, where the difference between two input signals is amplified.<ref name = b></ref>
==References==
{{reflist}}[[Category:Uploaded]]