An Approximate Closed-Form Transfer Function Model for Diverse Differential Interconnects

Abstract

This paper presents an approximate closed-form transfer function model for diverse differential interconnects. The proposed model is simple, intuitive, and can accurately describe various interconnects satisfying the validity conditions which theoretically bound the approximation error. The proposed model also provides a conceptual circuit representation by analogy with an equivalent circuit model of a single-ended interconnect. The model's accuracy is verified by comparing calculated through- and crosstalk-transfer functions against w-element SPICE simulation results for various LC-dominant and RC-dominant interconnects. Our analysis also empirically verifies that the approximation error is bounded by the validity parameters. In addition, the computation time is improved by about 157 times compared to that of the previous numerical computation method built-in SPICE simulator. With the proposed channel model, designers can easily understand and analyze the behaviors of various differential interconnects without complex analysis.