A tetrode transistor is any

transistor upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink). A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch e ...

having four active terminals.

Early tetrode transistors

There were two types of tetrode transistor developed in the early 1950s as an improvement over the

point-contact transistor The point-contact transistor was the first type of transistor to be successfully demonstrated. It was developed by research scientists John Bardeen and Walter Brattain at Bell Laboratories in December 1947. They worked in a group led by physicis ...

and the later

grown-junction transistor The grown-junction transistor was the first type of bipolar ''junction'' transistor made. It was invented by William Shockley at Bell Labs on June 23, 1948 (patent filed June 26, 1948), six months after the first bipolar point-contact transistor ...

and

alloy-junction transistor The germanium alloy-junction transistor, or alloy transistor, was an early type of bipolar junction transistor, developed at General Electric and RCA in 1951 as an improvement over the earlier grown-junction transistor. The usual construction o ...

. Both offered much higher speed than earlier transistors. *Point-contact transistor having two emitters. It became obsolete in the middle 1950s. *Modified grown-junction transistor or alloy-junction transistor having two connections at opposite ends of the base. It achieved its high speed by reducing the input to output

capacitance Capacitance is the capability of a material object or device to store electric charge. It is measured by the change in charge in response to a difference in electric potential, expressed as the ratio of those quantities. Commonly recognized are ...

. It became obsolete in the early 1960s with the development of the

diffusion transistor A diffused junction transistor is a transistor formed by diffusing dopants into a semiconductor substrate. The diffusion process was developed later than the alloy junction and grown junction processes for making bipolar junction transistors (B ...

Modern tetrode transistors

*Dual emitter transistor, used in two-input transistor-transistor logic gates *Dual collector transistor, used in two-output

integrated injection logic Integrated injection logic (IIL, I2L, or I2L) is a class of digital circuits built with multiple collector bipolar junction transistors (BJT). When introduced it had speed comparable to TTL yet was almost as low power as CMOS, making it ideal fo ...

gates * Diffused planar silicon bipolar junction transistor, - ''Tetrode transistor memory logic cell'', March 6, 1979. Filed September 6, 1977. used in some

integrated circuit An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny ...

s. This transistor, apart from the three electrodes (emitter, base, and collector), has a fourth electrode or grid made of conducting material placed near the emitter-base junction from which it is insulated by a silica layer. * Field-effect tetrode

References

External links

Some application aspects of the tetrode transistors
PDF (point contact)
The Tetrode Power Transistor
PDF (alloy junction)

(grown junction) Transistor types {{Electronic components

Early tetrode transistors

Modern tetrode transistors

See also

References

External links