Use of power supply current and output voltage observation for testing large mixed-signal devices

Power supply current monitoring is a promising technique for the development of new test methodologies for analogue and mixed-signal circuits, following the success attained in the digital domain. This paper shows that improved test efficiency and confidence is obtained when both functional output voltage and power supply current signals are observed. Results obtained from simulation of a number of circuits are presented comparing Fault Coverage, Normalised Deviation, and the Coefficient of Variation of faulty responses deviation amplitudes. Also, different test stimuli are compared to evaluate their suitability for testing.