Defect Oriented Testing for analog/mixed-signal devices

We present an application of Defect Oriented Testing (DOT) to an industrial mixed signal device to reduce test time and maintain quality. The device is an automotive IC product with stringent quality requirements and a mature test program that is already in volume production. A complete flow is presented including defect extraction, defect simulation, and test selection. A major challenge of DOT for mixed signal devices is the simulation time. We address this challenge with a new fault simulation algorithm that provides significant speedup of over 100x in the DOT process. Moreover, a number of methods are presented to improve the accuracy of this algorithm. Based on the fault simulations, we determine a minimal set of tests which detects all defects. The proposed minimal test set is compared with the actual test results of more than a million ICs. We prove that the analyzed production tests of the device can be reduced by at least 50%.