Improved coefficient based test for diagnosing parametric faults of analog circuits

In this paper an algorithm to identify parametric faults occurring in analog circuits using Transfer Function Coefficients (TFCs) is proposed. From the circuit description and component tolerance specifications, the tolerance boxes of all TFCs are pre computed for fault free circuit and faulty circuit with all possible single faults. For each fault ID a Fuzzy Inference System (FIS) is constructed based on the tolerance boxes of these TFCs. During the test, the actual TFCs are obtained and using the FIS the faulty element is identified. Reliability of the proposed method is verified through a benchmark circuit.