Fault observability analysis of analog circuits in frequency domain

We study the testability of analog circuits in the frequency domain by introducing the analog fault observability concept. The proposed algorithm indicates the set of adequate test frequencies and test nodes to increase fault observability. This approach combines a structural testing methodology with functionality verification to increase the test effectiveness and consequently the design manufacturability and reliability. We analyze the case of single fault, double, and multiple faults. Concepts such as fault masking, fault dominance, fault equivalence, and non observable fault in analog circuits are defined and then used to evaluate testability. The theoretical aspect is based on the sensitivity approach.