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The bipolar junction transistor, the first type of transistor to be mass-produced, is a combination of two junction diodes and is formed of either a thin layer of p-type semiconductor sandwiched between two n-type semiconductors (an n–p–n transistor), or a thin layer of n-type semiconductor sandwiched between two p-type semiconductors (a p ...
The common base current gain (or α) of a point-contact transistor is usually around 2 to 3, [4] whereas α of bipolar junction transistor (BJT) cannot exceed 1. The common emitter current gain (or β) of a point-contact transistor does not usually exceed 1, [4] whereas β of a BJT is typically between 20 and 200. Negative differential ...
Bipolar transistors, and particularly power transistors, have long base-storage times when they are driven into saturation; the base storage limits turn-off time in switching applications. A Baker clamp can prevent the transistor from heavily saturating, which reduces the amount of charge stored in the base and thus improves switching time.
Cross-sectional view of a MOSFET type field-effect transistor, showing source, gate and drain terminals, and insulating oxide layer. The field-effect transistor (FET) is a type of transistor that uses an electric field to control the current through a semiconductor. It comes in two types: junction FET (JFET) and metal-oxide-semiconductor FET ...
The invention of the high-electron-mobility transistor (HEMT) is usually attributed to physicist Takashi Mimura (三村 高志), while working at Fujitsu in Japan. [4] The basis for the HEMT was the GaAs (gallium arsenide) MOSFET (metal–oxide–semiconductor field-effect transistor), which Mimura had been researching as an alternative to the standard silicon (Si) MOSFET since 1977.
A phototransistor is a light-sensitive transistor. A common type of phototransistor, the bipolar phototransistor, is in essence a bipolar transistor encased in a transparent case so that light can reach the base–collector junction. It was invented by John N. Shive at Bell Labs in 1948 [6]: 205 but it was not announced until 1950. [7]
The introduction of the transistor is often considered one of the most important inventions in history. [1] [2] Transistors are broadly classified into two categories: bipolar junction transistor (BJT) and field-effect transistor (FET). [3] The principle of a field-effect transistor was proposed by Julius Edgar Lilienfeld in 1925. [4]
The original unijunction transistor, or UJT, is a simple device that is essentially a bar of n-type semiconductor material into which p-type material has been diffused somewhere along its length, fixing the device parameter (the "intrinsic stand-off ratio"). The 2N2646 model is the most commonly used version of the UJT.