1MHz High Efficiency LLC Resonant Converters with Synchronous Rectifier

Abstract

This paper proposes a novel synchronous rectifier driving scheme for resonant converters. An LLC resonant converter with proposed synchronous rectification is designed and analyzed. It is a high efficiency, high power density solution for future frond end converters. Hold up time extension capability is achieved for designed LLC resonant converter without sacrificing the efficiency for nominal condition. 1kW, 1MHz LLC resonant converter with proposed SR is built to demonstrate its advantages (size and efficiency) over the diode rectification and PWM converter. Overall 95.1% efficiency and 96W/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> power density are achieved.