Defect-oriented vs schematic-level based fault simulation for mixed-signal ICs

Escalating demand for mixed-signal Integrated Circuits has been accompanied by the need to develop efficient strategies to guarantee higher quality at lower cost. One key to achieving this is efficient production test and the utilization of Design-for-Testability (DfT). Fault simulation based test evaluation would be a major contribution towards measuring and optimizing the effectiveness of a production test. Fault simulations, however, are only useful if the underlying fault list generation approaches accurately reflect manufacturing defects-both in their probability of occurrence and in their electrical behavior. This paper evaluates and compares two fault list generation approaches and the implications on test optimization. Fault lists derived from both Inductive Fault Analysis (IFA) and a transistor fault-model are compared for a testability analysis on a self-test function for a high-performance switched-current design.