Concurrent fault simulation for mixed-signal circuits

The purpose of this research is to investigate general and fast fault simulation methodologies for analog and mixed-signal circuit testing. Mixed-signal test development has become increasingly difficult and expensive, due to the lack of analog fault simulators and automated test generation tools and the expensive specification-based analog test practices in industry. While digital concurrent fault simulators have been developed twenty years ago, the state-of-the-art in analog fault simulation is considerably behind. In this dissertation, fast concurrent fault simulation methodologies for general analog and mixed-signal circuits are investigated for the purposes of test evaluation, test generation, and fault diagnosis. A suite of novel algorithms are integrated to reduce the complexity of computation involved in every major aspect of the circuit simulation by sharing the intermediate results between faults been simulated. A general transient fault simulator for nonlinear analog circuits is developed and significant fault simulation speedup is obtained without any loss of accuracy in testing applications. Based on the concurrent fault simulation framework, partial numerical simulation methods are developed for efficient DC and transient test generation of analog circuits. For complex mixed-signal circuits, a novel concurrent fault co-simulation method is investigated and key issues of concurrent fault effects propagation between analog and digital circuits are addressed.