Tetrode transistor
Encyclopedia
Early tetrode transistors
There were two types of tetrode transistor developed in the early 1950s as an improvement over the point-contact transistorPoint-contact transistor
A point-contact transistor was the first type of solid-state electronic transistor ever constructed. It was made by researchers John Bardeen and Walter Houser Brattain at Bell Laboratories in December 1947. They worked in a group led by physicist William Bradford Shockley...
and the later grown junction transistor and alloy junction transistor. 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 capacitanceCapacitanceIn electromagnetism and electronics, capacitance is the ability of a capacitor to store energy in an electric field. Capacitance is also a measure of the amount of electric potential energy stored for a given electric potential. A common form of energy storage device is a parallel-plate capacitor...
. It became obsolete in the early 1960s with the development of the diffusion transistorDiffusion transistorA diffusion transistor is any transistor formed by diffusing dopants into a semiconductor substrate. Diffusion transistors include some types of both bipolar junction transistors and field-effect transistors...
.
Modern tetrode transistors
- Dual emitter transistor, used in two input transistor-transistor logicTransistor-transistor logicTransistor–transistor logic is a class of digital circuits built from bipolar junction transistors and resistors. It is called transistor–transistor logic because both the logic gating function and the amplifying function are performed by transistors .TTL is notable for being a widespread...
gates. - Dual collector transistor, used in two output integrated injection logicIntegrated injection logicIntegrated injection logic is a class of digital circuits built with multiple collector bipolar junction transistors . When introduced it had speed comparable to TTL yet was almost as low power as CMOS, making it ideal for use in VLSI integrated circuits...
gates. - Diffused planar silicon bipolar junction transistor, used in some integrated circuitIntegrated circuitAn integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
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 transistors having two gates.
External links
- Some application aspects of the tetrode transistors PDF (point contact)
- TRANSISTOR MUSEUM Historic Transistor Photo Gallery WESTERN ELECTRIC 3N22 (grown junction)
- The Tetrode Power Transistor PDF (alloy junction)