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 ...
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 physici ...
and the later
grown-junction 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.
Modern tetrode transistors
*Dual emitter transistor, used in two-input
transistor-transistor logic gates
*Dual collector transistor, used in two-output
integrated injection logic 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
See also
*
Multigate transistor.
*
Pentode transistor A pentode transistor is any transistor having five active terminals.
Early pentode transistors
One early pentode transistor was developed in the early 1950s as an improvement over the point-contact transistor.
*A point-contact transistor having thr ...
References
External links
Some application aspects of the tetrode transistorsPDF (point contact)
The Tetrode Power TransistorPDF (alloy junction)
(grown junction)
Transistor types
{{Electronic components