Fuzzy Techniques in Analog Circuit Design

The aim of his paper is to present some applications of fuzzy techniques in the optimization-based design of analog circuits. Our approach turns into profit the advantages offered by different fuzzy techniques. Fuzzy systems or fuzzy sets are involved in every algorithm phase. The optimization problem formulation is accomplished in a flexible manner using fuzzy sets to define fuzzy optimization objectives. Also, the initial guess of design parameters is based on matching degrees determined with fuzzy sets. The optimization engines use fuzzy systems to compute the coefficients to modify the design parameters in each iteration. In order to reduce the time spent for circuit performance evaluation, we use a fuzzy system to model each circuit performance. Two computer-aided design tools, at the cell level are developed in Matlab. A large collection of experimental results proves the validity of our approach. Different analog modules as simple transconductance operational amplifier, Miller operational transconductance amplifier, and common-emitter stage were designed for several sets of design requirements with very good results. Key-words: Analog design, Multiobjective optimization, Fuzzy sets, Fuzzy systems, Unfulfillment degree.