Analog IC Variability Bound Estimation Using the Cornish–Fisher Expansion

In nanoscale integrated circuit technologies, process parameter fluctuations gain increasingly in importance. Efficient methods are thus required during the design phase to evaluate the resulting variability. In this letter, we propose a new method to estimate the variation bounds of analog circuit performance. This method combines design of experiment techniques with the Cornish-Fisher expansion: process parameter variations are first mapped to circuit performance metrics by a quadratic model, and then an analytical approximation of the performance distribution's quantiles enables the enclosure of the performance variations. The proposed method demonstrates a better accuracy/efficiency ratio than Monte-Carlo-based methods.