Oscillation-test technique for CMOS operational amplifiers by monitoring supply current
A comparison of the merits and possibilities of considering the output voltage and the negative supply current as test observables when using the Oscillation-test technique is carried out. The method is applied to CMOS opamps considering an exhaustive analysis of catastrophic defects (opens, shorts), GOS and floating gates using HSPICE. We analyze deviations in both frequency and signal amplitude of each observable comparing their sensitivity to defects. Results show that the supply current peak value provides the highest defect coverage for a single opamp oscillator, while the oscillating frequency provides the highest fault coverage for a double opamp oscillator.
test observable oscillation-based test oscillation-test strategy analog and mixed-signal test supply current test compensated two-stage cmos opamps