Test effectiveness metrics for CMOS faults

The authors present two novel metrics (range effectiveness and differentiation effectiveness) for evaluating the effectiveness of continuous-domain test techniques, such as supply current and propagation delay testing, for CMOS faults of general severity. The metrics consider both the severity of the fault and the differentiation of test measurements. Range effectiveness is used to determine the range of fault severities that are reliably detected as being present in a circuit, and differentiation effectiveness is used to determine the differentiation between good and faulty circuits for a specified maximum acceptable fault severity. An application comparing supply current and propagation delay testing of a bridging fault is presented to illustrate the metrics