Parametric fault diagnosis using overdetermined system of fault equations

The paper shows a procedure for testing linear analog circuits using multi-frequency parametric fault diagnosis. Some methods for test frequency selection determine the total number of test frequencies equal to the total number of tested network parameters. The error between actual and estimated network parameters is evaluated only on several frequencies while the rest of the frequency band of the circuit is not taken into account. A new approach based on an overdetermined system of fault equations which can dramatically reduce the total error of the solution is presented. A practical example of application is shown on the test frequency selection of an EMI filter.