Process for providing electrostatic discharge protection to an integrated circuit output pad

摘要

An integrated circuit structure with input/output gate voltage regulation and parasitic zener and junction diodes for protection against damage resulting from electrostatic discharge (ESD) events. The circuit includes a first protective FET connected between an input/output pad and a ground potential of the integrated circuit. A diode voltage regulator is also connected between the gate of the first protective FET and a reference potential of the integrated circuit. The first protective FET receives a voltage from its gate-drain overlap capacitance during an ESD event. The diode is operative during an ESD event to provide a sufficient voltage to the first FET gate to permit a desired ESD current flow through the first protective FET. In one embodiment the first FET is an NMOS device and the diode voltage regulator is a series of p-n forward biased diodes.