Modulation Scheme for a ZVS Clamp-Switch Operated Three-Level Flying Capacitor Buck Converter

A modulation scheme to extend the zero-voltage switching (ZVS) range of a three-level flying capacitor buck converter is proposed. ZVS is achieved by employing a clamp-switch network parallel to the converter’s inductor and using the synchronous rectifier switches to control the inductor current during the freewheeling phase. So, the current value for discharging the device capacitances can be adjusted to achieve ZVS. The proposed modulation scheme is described and verified by simulation results and measurements on a prototype converter.