Shared electrostatic discharge protection for integrated circuit output drivers

摘要

A system for protecting metal oxide semiconductor field effect transistor (MOSFET) output drivers within an integrated circuit (IC) from an electrostatic discharge (ESD) includes a first MOSFET output driver and a second MOSFET output driver positioned within a common IC diffusion material. The system includes a contact ring coupled to the common IC diffusion material and arranged along an outer edge of a perimeter surrounding the MOSFET output drivers. A centroid of each MOSFET output driver is common with a centroid of the perimeter surrounding both MOSFET output drivers. Each MOSFET output driver has a value of substrate resistance (Rsub) that initiates bipolar snapback in the MOSFET output driver at which an ESD event occurs. The value of Rsub depends upon a composite distance from the centroid of each MOSFET output driver to the contact ring.