Analog CMOS realization of fuzzy logic membership functions

The design of a monolithic CMOS analog function synthesizer based on a current-mode algorithm and its application in fuzzy membership function synthesis is presented. The proposed circuits require only one reference current, independently of the course or the number of implemented functions. The networks are temperature and technology insensitive. Other features are a small chip area and a simple design process for any arbitrary functions. Matching considerations allow a prediction of the available approximation accuracy. Theoretical evaluations are validated by measurements of several membership functions fabricated in an experimental 1.0-μm CMOS technology