A CMOS reference-less membership function generator

In this paper a reference-less membership function generator (MFG) is proposed to avoid off-chip reference generation. In this MFG a fewer number of pins are needed for the adjustment of the membership functions properties. Therefore, more number of pins are left free for fuzzy controller to transmit information through these pins. This MFG accepts differential input voltages and generates differential output currents. The output is adjustable by means of changing the size of the transistors. Due to differential structure, Major part of power supply noise is rejected. The Hspice (level 49) simulation results are given using a generic 0.35μm standard CMOS technology parameters and power supply of 3.3V. Because of simple and symmetrical circuitry, layout of the proposed MFG is very compact.