ESD protection circuit with improved trigger-on voltage

摘要

An electrostatic discharge (ESD) protection circuit includes at least one MOS transistor coupled between a power supply and ground. A voltage differentiation module is coupled between a gate and a substrate of the MOS transistor, such that a voltage difference is created between the gate and the substrate. Accordingly, a surface current path of the transistor is created in addition to a substrate current path from the gate to the substrate for dissipating an ESD current thereacross, during an ESD event. This improves a trigger-on voltage of the ESD protection circuit.