Fault Diagnosis of Analog Circuits with Tolerance Based on Simulation-before-Test and Distance Algorithm

Fault dictionary is the most practical method of fault diagnosis in analog circuit. Before analog circuit with tolerance is diagnosed, circuit is simulated by computer. Typical parameters of every state are used to build fault dictionary. Distance algorithm is used to calculate the similarity between current circuit and every state of fault dictionary. Analog circuit with tolerance can be diagnosed by the distance. Firstly, the method of simulation-before-test is introduced to build fault dictionary. Secondly, familiar distance algorithm is resumed, such as Euclidean distance. Finally, an example of fault diagnosis of analog circuit with tolerance is provided. In the example, simulation-before-test and distance algorithm are combined to diagnose analog circuit with tolerance. Two distance methods are compared to explain the advantages and disadvantages of the Euclidean distance algorithm.