Abstract
We have developed an operation-region (OR) model for abstractly modeling the behavior of analog and mixed-signal circuits. The model is based on observing changes in the operation regions of MOS transistors. In this paper, we propose an analysis method for analog and mixed-signal circuits by applying the OR model and apply our method to test ITC'97 benchmark circuits. We also propose and verify a more efficient method of applying the OR model. To enhance the usability of the model, we try to implement it by using an X-Y curve method. This implementation maps transistor ORs to observable values and provides the capability to represent common conditions showing behaviors caused by many faults.