An intelligent framework for designing analog circuits based on hybrid reasoning

In this paper an intelligent CAD tool for the design of analog circuits is presented. First, the system uses fuzzy rule based reasoning to select alternative architectures for the circuits at each level of hierarchy and then deduces the device sizes via case-based reasoning whose objective is to determine the plausible building blocks subspecifications on the basis of past design experiences. In the case that there are some specifications which have not been met yet, qualitative reasoning-based approach would be used to make final correction. The above approach is demonstrated through the example of a CMOS op-amp