A ZVS High Step-Down Converter With Reduced Component Count and Low Ripple Output Current

Abstract

In this paper, a new synchronous rectified converter with ultra-low output current ripple and high voltage attenuation is proposed. The presented converter can achieve soft switching without requiring any additional active components, leading to high efficiency while maintaining the simplicity of conventional converters. Other main features of the proposed circuit are inherent shoot-through protection, reduced current stress of the semiconductors due to the coupled inductor, and low voltage stress across the low-side MOSFET. In addition, a pulse frequency modulation control scheme is used, which allows for an extended soft-switching range without imposing an excessive circulating current at light loads. The steady-state analysis and experimental results from a 120 W prototype are presented in this paper.

Keywords

• High step-down converter
• coupled inductor converter
• duty cycle extension
• synchronous rectification
• zero voltage switching