Implementation of an application-specific fuzzy controller by means of a mixed-signal sequential architecture

A mixed-signal VLSI circuit that efficiently maps the processing required for a fuzzy knowledge-based controller (FKBC) is presented. The proposed architecture is constituted by digitally programmable continuous-time blocks to perform inference and switched-current memory cells to store in current-mode the partial information resulting from its pipeline operation. This FKBC is intended to provide multidimensional nonlinear function approximation for switching power converter optimum control. Details of a new pulse-width-modulated defuzzyfication scheme are included. Transistor level post-layout simulation results for a 0.8 μm CMOS technology are included which validate the different block operations, their compatibility and the feasibility of the sequential architecture