MOS transistor output circuit

摘要

An MOS transistor output circuit includes a parallel combination of first and second circuits including transistors of different output characteristics in either or both of paths between an output terminal and a point of ground potential and the output terminal and a VDD voltage supply terminal. Upon transition of an input signal level, both first and second circuit become conductive so that the output circuit exhibits a large current driving capability which permits the output voltage to rapidly change until it approaches a predetermined level. When the output voltage reaches the predetermined level, one of the first and second circuits is turned off to thereby prevent the output circuit ON-resistance RON from becoming excessively small, which, in turn, limits the circuit driving capability, whereby ringing in the output voltage is effectively prevented.