A pass transistor acts as a simple series switch in logic circuits, passing a voltage level from its input to its output when its gate is driven active. Unlike standard CMOS gates that actively pull outputs to VDD or ground, pass-transistor logic can reduce transistor count and save area. However, it suffers from voltage drops across the junction, often requiring buffer stages to restore logic levels.
We used a pass transistor network for the multiplexer to save die area, but the signal degradation means we need a restorer at the output.
Related terms
CMOS
Complementary metal-oxide-semiconductor is the dominant fabrication technology for integrated circuits.
MOSFET
A metal-oxide-semiconductor field-effect transistor is a voltage-controlled switch used to amplify or switch electronic signals.
Gate array
A prefabricated silicon chip containing unconnected logic gates.