Distributed Selection of the Optimal Sizes of Analog Unity Gain Cells by Fuzzy Set Intersection

Abstract

A distributed system based on Fuzzy sets to select the optimal sizes of Unity Gain Cells (UGCs) is introduced. A zoom technique is also introduced to search for the optimal sizes in a more refined way. The selected sizes accomplish target specifications established by linguistic variables, namely gain “closer to” unity and “large” bandwidth, which are represented by fuzzy sets. The case of study is focused on three Voltage Follower and a CFOA whose performance characteristics are evaluated by using IC technology of 0.35µm and 180µm, respectively, and the circuit simulation program SPICE. Every circuit is codified by the width and large (W/L) of every Metal-Oxide-Semiconductor Field-Effect-Transistor (MOSFET) and by its bias current source. From the population of feasible solutions computed by evolutionary algorithms, the optimal W/L sizes are selected by the proposed distributed system through the intersection of fuzzy sets.