AC/DC BIST for testing analog circuits

In this paper, we present a new BIST approach for testing analog circuits. It uses current window comparator and current-based checker circuits for processing the AC and DC test responses of analog parts in mixed-signal integrated circuits. In embedded operational amplifiers of analog and mixed-signal circuits, there are faults that cannot be detected or are difficult to detect (detecting around the cutoff frequency) when voltage-based test stimuli are used. Our investigations have shown that a large number of the above faults can be easily detected by deriving built-in DC test signals. Linear analog filters have been considered as test vehicles and simulation results show the feasibility and effectiveness of the proposed BIST approach.