Observer-based test of analog linear time-invariant circuits

An observer-based test methodology is proposed for detecting parametric faults in analog linear time-invariant circuits. A Kalman filter is used to reduce the measurement noise. Experiments conducted on an analog circuit are used to test the viability of the test methodology. The paper also discusses some inherent limitations of analog test in general. We show that, in the analog test domain, a fault-free parameter may mask the detection of a faulty parameter. Moreover, one faulty parameter may mask the detection of another faulty parameter leaving them both undetected.