Constant frequency PWM capacitor voltage-clamped series resonant power supply

The authors propose a capacitor-voltage-clamped series-resonant converter, regulated at constant frequency by pulse-width modulation (PWM), that is suitable for an offline isolated multiple output power supply. The principle of operation, theoretical analysis, simulation, design procedure, and design example are provided, along with experimental results. The validity of the theoretical analysis and the main properties of the proposed converter were demonstrated in the laboratory, with the design and construction of an isolated power supply rated at 12 V/16 A and operating at 100 kHz. The proposed technique significantly reduces the RMS value of the current through the transistors, reduces the size of the output filter capacitor, and improves dynamic response