Concurrent Stimulus and Defect Magnitude Optimization for Detection of Weakest Shorts and Opens in Analog Circuits
Barry John Muldrey, Sabyasachi Deyati, Abhijit Chatterjee · 2016
We present a methodology for algorithmic generation of test signals for the detection and diagnosis of a variety of short and open-circuit defects in analog circuits. Prior algorithms have focused on test generation for known short or open defect values. This places the burden of failure coverage on accurate analysis of observed defects in known failed parts at high cost. In this work, we optimize the test stimulus to detect theweakestshorts and opens in analog circuits using a concurrent stimulus and defect value optimization algorithm. Since the defect value itself is an optimization parameter, the responses of nonlinear circuits corresponding tomultiple defect valuesare considered as opposed to asinglelinearized representation corresponding to a fixed defect value as in the existing state of the art. The algorithm produces a test stimulus along with the values of the weakest shorts and opens that the stimulus can detect (the locations of the defects are specified to the algorithm). These values are determined by the design of the analog circuit itself and therefore subsume all specified detectable defects for the circuits concerned. Experimental results show the feasibility of the proposed approach on selected test cases and defect sets.