A Novel Multiple Membership Function Generator for Fuzzy Logic Systems

This paper presents a new multiple membership function generator which is capable of forming Gaussian, trapezoidal, triangular, S-shaped, and Z-shaped membership functions. To the best of authors' knowledge, a single circuit that can concurrently generate Gaussian, trapezoidal, and triangular membership functions has not been reported in the literature yet. Proposed circuit is compatible with many fuzzy logic systems requiring different types of membership functions. The circuit is designed using a commercial 0.18 mu m CMOS technology and consumes a total power of 180 mu W. The shapes of each membership function can be modified by properly chosen values of input and reference voltages. Functionality of all membership functions is validated across process corners with additional Monte Carlo analysis where temperature variations are considered, as well.