What (who) is bipolar transistor - definition

TRANSISTOR THAT USES BOTH ELECTRONS AND HOLES AS CHARGE CARRIERS

BJT; P-n-p transistor; N-p-n transistor; Bjt; Bipolar junction transistors; Bipolar Junction Transistor; Collector current; Bjt transistor; Emitter, base, and collector; Ebers-Moll; PNP (transistor polarity); Ebers-Moll model; PNP transistor; NPN transistor; Transistor beta; Ebers–Moll model; Bipolar transistor; Bipolar transistors; Power BJT; Junction transistor; P–n–p transistor; N–p–n transistor; H-parameter model; Emitter, base and collector; Emitter current; VBIC

bipolar transistor

<electronics> A transistor made from a sandwich of n- and p-type semiconductor material: either npn or pnp. The middle section is known as the "base" and the other two as the "collector" and "emitter". When used as an amplifying element, the base to emitter junction is in a "forward-biased" (conducting) condition, and the base to collector junction is "reverse-biased" or non-conducting. Small changes in the base to emitter current (the input signal) cause either holes (for pnp devices) or free electrons (for npn) to enter the base from the emitter. The attracting voltage of the collector causes the majority of these charges to cross into and be collected by the collector, resulting in amplification. Contrast field effect transistor. (1995-10-04)

Bipolar junction transistor

A bipolar junction transistor (BJT) is a type of transistor that uses both electrons and electron holes as charge carriers. In contrast, a unipolar transistor, such as a field-effect transistor, uses only one kind of charge carrier.

https://en.wikipedia.org/wiki/Bipolar_junction_transistor

BJT

Bipolar Junction Transistor (Reference: IC)

Wikipedia

Bipolar junction transistor

A bipolar junction transistor (BJT) is a type of transistor that uses both electrons and electron holes as charge carriers. In contrast, a unipolar transistor, such as a field-effect transistor, uses only one kind of charge carrier. A bipolar transistor allows a small current injected at one of its terminals to control a much larger current flowing between the terminals, making the device capable of amplification or switching.

BJTs use two p–n junctions between two semiconductor types, n-type and p-type, which are regions in a single crystal of material. The junctions can be made in several different ways, such as changing the doping of the semiconductor material as it is grown, by depositing metal pellets to form alloy junctions, or by such methods as diffusion of n-type and p-type doping substances into the crystal. The superior predictability and performance of junction transistors quickly displaced the original point-contact transistor. Diffused transistors, along with other components, are elements of integrated circuits for analog and digital functions. Hundreds of bipolar junction transistors can be made in one circuit at very low cost.

Bipolar transistor integrated circuits were the main active devices of a generation of mainframe and minicomputers, but most computer systems now use CMOS integrated circuits relying on field-effect transistors. Bipolar transistors are still used for amplification of signals, switching, and in mixed-signal integrated circuits using BiCMOS. Specialized types are used for high voltage switches, for radio-frequency amplifiers, or for switching high currents.

https://en.wikipedia.org/wiki/Bipolar junction transistor