Oscillation Based Testing for Low Voltage Two Stage Operational Transconductance Amplifier

The paper describes the design for testability (DFT) of low voltage two stage operational transconductance amplifiers based on oscillation based testing (OBT). The oscillation-test strategy is a low cost and robust test method for mixed-signal integrated circuits. Being a vectorless test method, it allows one to eliminate the analog test vector generator. Circuit under test is transformed to oscillators using very simple techniques. The tolerance band of the oscillation frequency is determined by a Monte Carlo analysis taking into account the nominal tolerance of all circuit under test components. Seventeen bridging faults and nine open faults have been analyzed in proposed work. Simulation results for two stage operational transconductance amplifier using a 0.18 m CMOS technology show that the proposed oscillation-based test strategy has more than 92% fault coverage and, with a minimum number of extra components, requires a negligible area overhead.