An Adaptive Delay Model for Timing Yield Estimation under Wide-Voltage Range

Abstract

Yield analysis for wide-voltage circuit design is a strong nonlinear integration problem. The most challenging task is how to accurately estimate the yield of long-tail distribution. This paper proposes an adaptive delay model to substitute expensive transistor-level simulation for timing yield estimation.We use the Low-Rank Tensor Approximation (LRTA) to model the delay variation from a large number of process parameters. Moreover, an adaptive nonlinear sampling algorithm is adopted to calibrate the model iteratively, which can capture the larger variability of delay distribution for different voltage regions. The proposed method is validated on benchmark circuits of TAU15 in 45nm free PDK. The experiment results show that our method achieves 20-100X speedup compared to Monte Carlo simulation at the same accuracy level.