A scalable substrate noise coupling model for mixed-signal ICs

Abstract

A scalable macromodel for substrate noise coupling in heavily doped substrates has been developed. This model is simple since it requires only four parameters which can readily be extracted from a small number of device simulations or measurements. Once these parameters have been determined the model can be used for any spacing between the injection and sensing contacts and for different contact geometries. The scalability of the model with separation and width provides insight into substrate coupling and optimization issues prior to and during the layout phase. The model is validated for a 2 /spl mu/m and a 0.5 /spl mu/m CMOS process where it is shown that the simple model predicts the noise coupling accurately. Measurements from a chip fabricated in a 0.5 /spl mu/m CMOS process show good agreement with the model.