Synchronous rectification with low voltage MOSFETs in LLC converters

This paper deals with the optimized application of low voltage power MOSFETs in high frequency LLC DC-DC converter as synchronous rectification switches. The used semiconductor devices are trench MOSFET with improved figure of merit (FOM). The value of such a quantity is a good indicator that the MOSFET devices can operate at both high switching speed and extended current capability, as they are required in these DC-DC converter applications. Firstly, the design of low voltage MOSFETs as synchronous rectification switches is treated and discussed. Furthermore, an extended characterization of trench MOSFETs on experimental boards of a LLC DC-DC power converter is carried out.