CMOS output circuit

摘要

A CMOS output circuit including CMOS inverters, is formed on a semiconductor substrate and N MOS switching transistors are provided. The output circuit is responsive to an external control signal for switching a plurality of reference voltages and delivering them as multiple-level drive signals. The CMOS output circuit furthermore includes PMOS switching circuits connected in parallel with each of a plurality of CMOS transfer gates, CMOS inverters, and N MOS switching transistors for preventing a latch-up phenomenon of the CMOS inverters from being produced. The PMOS switching circuits are on-off controlled by a control signal obtained by converting an amplitude level of an external control signal.