Research of Design-for-Testability of CMOS Image Sensor

CMOS image sensor has experienced explosive growth in recent years. As increasing of number of pixel scale and complexities of circuit, testability of image sensor chip has become an important problem that must be dealt with by both design and test engineers. A systematic approach to handle testability of CMOS image sensor circuits is urgently needed, because current test methods less address this domain. In this paper, a uniform and systematic approach is explored to the testability problem of CMOS image sensor, and it covers the image sensor defect analysis, fault model definition and test system design. The experimental data shows the fault coverage can be up to 99.3%.