A physical and analytical model for substrate noise coupling analysis

This work presents a new approach for computing the equivalent circuit models for substrate noise coupling in mixed-signal integrated circuits,. An analytical model is derived from a physical understanding of the various coupling paths in a heavily doped silicon substrate. The approach has been validated with measured data from a 0.35 μm CMOS process and demonstrates that the coupling mechanisms are complex whereby simple resistance expressions cannot be used to predict substrate noise coupling without the need for extensive computer simulations using three-dimensional finite difference or Green´s function solvers.