An improved novel driving scheme of synchronous rectifiers for LLC resonant converters

This paper proposes an improved novel synchronous rectifier (SR) driving scheme for resonant converters. It is very suitable for high frequency, high efficiency and high power density dc-dc resonant converters with SRs. An LLC resonant converter with proposed synchronous rectification is designed and analyzed. With proposed driving scheme, SR body diode conduction is almost reduced to none. The reverse recovery problem of SRs is eliminated. Both current and voltage stress are greatly decreased. Conduction loss and switching loss of SRs are considerably reduced. The experimental results show that the proposed LLC resonant converter with SR can achieve low stresses, high efficiency and high power density