CMOS high voltage drive output buffer

摘要

A CMOS high voltage drive output buffer that protects the drive stage from seeing relatively high voltages (e.g., 5 V) during "hot pluggable" conditions (that is, when the reference voltage VDD is not present). A transmission gate and clamping transistors are disposed around the output devices to provide the requisite protection. A backgate bias generator for use with P-channel devices is also disclosed that is capable of withstanding "hot pluggable" conditions.