An adaptive simulation framework for AMS-RF test quality

Ensuring the quality of a circuit implies ensuring the quality of test. Despite the fact that performance-based testing has been the golden standard for Analog, Mixed-Signal and RF test for decades, high-reliability markets like automotive have found that functional test leaves some potential defects undetected that can produce in-field failure. There is thus a push towards defect-oriented testing which, in turn, calls for an efficient defect simulation framework. This paper presents a statistical adaptive defect simulation based on likelihood-weighted random sampling to evaluate the quality of AMS-RF tests in terms of defect coverage and fault escape. The adaptive loop takes a decision at each new defect simulation on whether it is more efficient to assess the defect coverage or the fault escape rate of the test under evaluation, as a function of the desired targets for these two metrics. Several decision criteria are proposed and validated by simulation of a complete IC for different tests.