An FPGA-based mixed-signal controller for switching mode converters

An FPGA-based mixed-signal voltage-mode controller for switching mode converters is investigated in this paper. The proposed control architecture contains an FPGA, a DAC and a comparator, where the FPGA is a control processor that implements DPWM generation and a PID control algorithm. The DAC in conjunction with the comparator operates in two operational modes: one is a conversion mode performing successive approximation A/D conversion, and the other is a modulation mode providing an instant pulse-width modulator in the analog domain. The fast response of this mixed-signal control architecture makes itself close in dynamic behavior to its analog counterpart. Furthermore, the proposed solution is also effective, since all components used are viable for power integration. Its features and performance are sufficient to promote itself for implementation in many industrial digital control systems.