Applying a counter-based PWM control scheme to an FPGA-based SR forward converter

In this paper, a field programmable gate arrays (FPGA) technique applied to a forward converter with synchronous rectification (SR) is utilized to design a pulse-width-modulation (PWM) proportional-integral-derivative (PID) controller, along with protection peripherals. With only one comparator and without any analog-to-digital converter (ADC), the information on the feedback output voltage is entirely obtained according to a counter, thereby causing full digitalization and easy implementation of this control topology using system on programmable chip (SOPC). In this paper, the detailed operation of such a control topology is described, along with some experimental results to demonstrate its effectiveness