Compact substrate models for efficient noise coupling and signal isolation analysis

Current propagation within a lightly doped substrate is approximated with a half-ellipse to efficiently estimate substrate resistances. As opposed to existing work, the proposed model contains only one fitting parameter. Compact models are also developed to determine the isolation efficiency of several commonly used structures such as a guard ring and triple well. The accuracy of these models is verified by comparing the models with a commercial substrate extraction tool based on a boundary element method. These models are used to compare several isolation structures within an industrial mixed-signal circuit with a lightly doped substrate.