Transistor Threshold Logic Gates

摘要

Threshold gates can be built using many types of devices such as transistors, tubes, tunnel diodes, and silicon controlled switches. The transistor threshold gate is studied here because of its small size, low power dissipation and good transition characteristics. The importance of sensitivity depends upon the logical function being realized. Complex functions require a less sensitive gate. State transition speed is limited by saturation and by high impedance levels. Using low impedance current mode gates this limit is reduced. ECAP (Electronic Circuit Analysis Program) is employed in the design of threshold gates. Examples of both saturated and current mode transistor threshold gates are presented and compared. (Author)