Method and system for improved noise isolation in an electrostatic discharge protection scheme

Abstract

An electrostatic discharge (ESD) protection scheme is provided that reduces EMI noise propagation among functional circuit blocks of an integrated circuit (IC). Traditional ESD protection schemes include an ESD bus electrically tied to the substrate of an integrated circuit (e.g., a P-well) and substrate well regions associated with electromagnetic interference (EMI) aggressor and sensitive circuits. These electrical couplings can propagate EMI noise on the ESD bus throughout the circuit blocks of the IC. Embodiments provide an ESD bus that is not tied to the substrate well regions associated with EMI aggressor and sensitive circuits of the IC, but instead is a separate conductive layer electrically coupled to an external ground. In this manner, the device circuits are isolated from EMI noise carried in the ESD bus, thereby protecting the various functional blocks from such noise.