Minimizing production test time to detect faults in analog circuits

Analog testing is a difficult task without a clearcut methodology. Analog circuits are tested for satisfying their specifications, not for faults. Given the high cost of testing analog specifications, it is proposed that tests for analog circuits should be designed to detect faults. Therefore analog fault modeling is discussed. Based on an analysis of the types of tests needed for different types of faults, algorithms for fault-driven test set selection are presented. A major reduction in testing time should come from reducing the number of specification tests that need to be performed. Hence algorithms are presented for minimizing specification testing time. After specification testing time is minimized, the resulting test sets are supplemented with some simple, possibly non-specification, tests to achieve 100% fault coverage. Examples indicate that fault-driven test set development can lead to drastic reductions in production testing time