Low-Voltage Wide Tuning Range Membership Function Generator and Its Application.

A versatile low-voltage CMOS circuit with a trapezoidal transconductance characteristic and independently programmable slope, height and horizontal position is designed in 0.18 mu m standard CMOS technology. The proposed circuit is constructed from combination of two linearization methods to enhance the linearity in low voltage applications. A -118 dB THD was obtained for a 400mV peak to peak differential input voltage at 125 KHz. Simulation results using HSPICE that verify the functionality of circuit with 1.5V supply are presented. The total power consumption is only 120 mu W. The circuit can find application in the implementation of membership functions in analogue and mixed-signal neuro-fuzzy systems.