Fault diagnosis of analog circuits based on phasor circle model

Algorithm of phasor circle model, a fault modeling on complex plane for fault dictionary in time domain analysis of linear analog circuit, is presents. The proposed algorithm achieved to characterize all potential fault status of each component with a circle on complex plane, using a voltage measurement approach on the only output node, and the unified mathematical formula of all complex circle is also presented with the parameters of center coordinate and radius. Furthermore, an approach of design for testability is discussed to minimize the ambiguous group. This algorithm can be used for identifying both soft fault and hard fault. Finally, an example circuit is presented to verify the efficient of the proposed algorithm.