Non-intrusive detection of defects in mixed-signal integrated circuits using light activation

© 2017 IEEE. The quality level of mixed-signal ICs lags behind the below-part-per-million defect test escape rates of digital ICs, as a result of the traditional testing based on performance specifications. Methods increasing the controllability to solve the problem of the low fault coverage of analog and mixed-signal circuits are in practice limited due to the excessive area overhead they require and their impact on the normal circuit operation. This paper presents a non-intrusive method to improve the controllability using light as an activation mechanism. The necessary simulation models are introduced to use the proposed method in the context of a defect-oriented test approach. This work also describes a workflow which enables the application of the method to large-scale industrial circuits. Finally, effective results are shown on an industrial mixed-signal front-end circuit under test (CUT) demonstrating around 27% increase in the number of detectable defects.