MIXED CURRENT VOLTAGE OBSERVATION TOWARDS EFFECTIVE TESTING OF ANALOGAND MIXED-SIGNAL CIRCUITS/

Power supply current monitoring is a promising technique for the devel opment of new test methodologies for analog and mixed-signal circuits. The advantages of efficiency and reduced test time have already been recognized in the digital domain. This paper shows that improved test efficiency and detection confidence are obtained when both output volt age and power supply current are observed. Results found from the simu lation of two circuits are presented comparing fault detection ratios and the amplitude of faulty response deviations when observing each on e of these signals. Cross-correlation between output voltage and power supply current is presented as a means to perform a single mixed curr ent/voltage testing operation, providing at the same time increased ef ficiency. It allows also for simplifications on test circuitry and pro cessing, as reductions on the sampling rates and amplitude resolutions used to acquire the signals provide the same fault coverage levels ob tained using higher fidelity measurements.