Circuit and method for a transistor-transistor logic (TTL) compatible output drive

摘要

A circuit (10) for providing TTL logic signals at an output (24) employs dual pull up devices (20, 30) at the output. The first device (20) is a bipolar transistor that acts as an emitter-follower to quickly pull up the output in response to applied logic signals to drive the output to a logic one state. Thereafter, the second device (30) which is a MOS transistor is turned on to drive the magnitude of the high logic output signal to substantially VCC, the positive power supply voltage supplied to the circuit (10).