Efficient fault diagnosis in analogue circuits using a branch decomposition approach

A branch decomposition approach for fault diagnosis in analogue circuits is presented. Two fault models for the fault simulation of operational amplifier circuits are also proposed. The method uses linear fault diagnosis (FD) equations based on Kirchhoff´s current law and nodevoltage measurements under the desired current excitations. The circuit is divided into subnetworks and appropriate interconnections. The checking of the consistency of the FD equations using nominal element values and the measured node voltages leads to the location of the faults in the circuit. The procedure can be applied to linear or nonlinear circuits for the location of single and multiple faults. Demonstrative examples of passive and active circuits are given to show the effectiveness of the proposed method.