A low-power, fully programmable membership function generator using both transconductance and current modes

Abstract

In this paper, a membership function generator (MFG) is presented which can produce triangular, trapezoidal, S-shaped or Z-shaped membership functions. The presented structure can operate in both trans-conductance (voltage–current) and current mode (current–current) with high programmability. The slope (keeping the height or width of the membership function constant), height (keeping the width constant) and width (keeping the height constant) of the membership function are independently programmable. Moreover, the width of the trapezoid can be varied without changing slope or height and all the generated shapes can be positioned horizontally. The topology, primarily, is presented in transconductance mode which can be converted to current mode with a little change in the input section of the circuit. Simulation results for the proposed circuit are presented in two operation modes. The most remarkable feature of the proposed MFG is its capability of generating outputs while consumes a very low amount of power. The analytical analysis of the proposed circuits is also given in HSPICE using TSMC 0.18 μm CMOS technology.