Self-biased electrostatic discharge protection method and circuit

Abstract

A self-biased electrostatic discharge (ESD) protection circuit for protecting an integrated circuit operating in a normal voltage range that includes both positive and negative voltage levels is disclosed. The self-biased ESD protection circuit includes an input connection for receiving an input voltage, a protection transistor electrically coupled to the input connection, and an electrical sink. The protection transistor is operable to provide ESD protection from the input connection to the electrical sink. The self-biased ESD protection circuit also includes a metal oxide semiconductor (MOS) biasing network electrically coupled to the input connection and the protection transistor. The MOS biasing network is operable to cause the protection transistor to remain in a non-conductive state when the input voltage is in the normal operating voltage range. Upon the occurrence of an electrostatic discharge event at the input connection, the protection circuit becomes conducting to discharge ESD current from the input connection to the electrical sink.