Pull-up type differential bus driver for signal transmission between semiconductor chips, supplies higher voltage to PMOS transistor only when voltage of either of signal lines is higher

摘要

Switching units (33,34) are connected between the downstream side of constant current source (V1) and signal lines (22,23). ON-OFF switching of switching units is controlled by respective differential input signals. When either of signal lines (22,23) having higher voltage is supplied, current does not flow into power supply line from one side or both sides of signal lines using control circuit. An Independent claim is also included for pull-up type differential drive procedure.