Novel pulse-width-modulated current-mode analog defuzzifier for the fuzzy control of switching DC-DC converters

In this communication, the authors propose a current-mode analog circuit solution for the defuzzying step required for the fuzzy-knowledge-based control (FKBC) of switching DC-DC converters. Considering the modulation of pulse widths needed for the control of switched power plants, the division operation at the output layer of a fuzzy inference controller takes advantage of the implicit signal-to-time conversion in the PWM process. This theoretical aspect is complemented with the proposal of a high-speed current-mode division circuit, which allows a wide range of switching frequencies. The PWM division circuit is preceded by a switched-current integrator to obtain a full defuzzifier. HSPICE layout-extracted transistor-level simulations for a standard CMOS 0.8 /spl mu/m technology verify the functionality of both the proposed defuzzifying method and circuit.