A simple CMOS-based membership function circuit

Tokmakci M., Alci M., Kilic R.

ANALOG INTEGRATED CIRCUITS AND SIGNAL PROCESSING, vol.32, no.1, pp.83-88, 2002 (SCI-Expanded) identifier identifier


In this study, design and analysis of a voltage-input current-output simple CMOS-based Membership Function Circuit (MFC) is presented. The proposed MFC is based on simple OTA structure and current-mode maximum circuits. This MFC implements basic four membership functions (trapezoidal, triangle, Z-shape and S-shape). The characteristics (width, height, slope and position) of the implemented membership functions are easily adjustable and it is suitable for current-mode fuzzy hardware. While the circuit's membership function characteristics have been confirmed by PSPICE-DC simulations, the circuit's transient response has been analyzed applying up to 10 MHz input signals in continuous time by PSPICE Transient simulations.