A Coarse Model for Estimation of Switching Noise Coupling in Lightly Doped Substrates

The objective of this paper is to propose a coarse model for coupling of switching noise through lightly doped substrates. This could be achieved by assuming a regular placement of substrate contacts in a digital aggressor. Additionally, an approximation of equal ground bounce in an entire digital aggressor is applied. The proposed model is aimed for use as an estimation before placement, i.e. before knowing the exact layout details. Consequently, this model could be utilized as a guideline for determining the optimal floorplanning of digital blocks with regards to substrate noise coupling to sensitive analog modules. Extraction code is written in MATLAB. Evaluation of the model has shown that reasonable accuracy of the estimation could be expected and that the proposed method could be used as a baseline for early exploration of substrate noise characteristics of the design.