Novel Clamp Diode to Mitigate the Voltage Oscillation of Low Voltage Rectifier Diodes in Asymmetric Half-Bridge Converter

Abstract

This paper proposes a novel clamp diode for the asymmetric half-bridge (AHB) converter. The proposed clamp diode is connected between the rectifiers and the output capacitor, and the voltage oscillation of the rectifier diodes with the low voltage is clamped to the output voltage. Meanwhile, the proposed clamp diode has no additional inductance between it and the rectifier diode. Therefore, no additional resonance occurs in the rectifier diodes, and the voltage oscillations are completely clamped to the output voltage. Consequently, by utilizing the proposed clamp diode in the AHB converter, the conduction loss can be reduced by applying rectifier diodes that have lower voltage stress compared to the conventional. Therefore, the proposed converter structure is suitable for achieving high efficiency. The practicability of the proposed converter was validated using 300W prototypes operating under input conditions of 360-400V and output conditions of 48V.