Quasi-Resonant Converter with Divided Resonant Capacitor on Primary and Secondary Side

H. Shiroyama, H. Matsuo, and Y. Ishizuka (Japan)


Power Electronics, quasiresonant converter, surge voltage, high efficiency


This paper presents a quasi-resonant converter with divided resonant capacitor on primary and secondary side. A conventional quasi-resonant converter using flyback topology can realize soft switching with simple circuit. However, relatively large surge voltage is applied to switching device. To decrease such surge voltage, resonant capacitor is divided on primary side and secondary side in the proposed converter. At first, the characteristics of proposed converter are analyzed using simulation to find optimum design. Then the 19V/5A prototype is fabricated to verify the effect of divided resonant capacitor. As the result, the voltage applied to switching device of proposed converter has been 26% lower than that of conventional converter. In addition, efficiency of proposed converter has been 1% higher than that of conventional converter.

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