Tetrode transistor

A tetrode transistor is any transistor 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 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.[1] It achieved its high speed by reducing the input to output capacitance. 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,[2] used in some integrated circuits. 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 tetrodes

References

  1. Wolf, Oswald; R. T. Kramer; J. Spiech; H. Shleuder (1966). Special Purpose Transistors: A Self-Instructional Programmed Manual. Prentice Hall. pp. 98–102.
  2. U.S. Patent 4,143,421 - Tetrode transistor memory logic cell, March 6, 1979. Filed September 6, 1977.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.