Precision Gate Drive Featuring High Dead-Time Resolution for Soft Switched Converters

Abstract:
One of the biggest disadvantages of silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) is the increased forward voltage of the internal body diode. In soft-switched applications a certain minimum dead-time is necessary to achieve zero-voltage-switching (ZVS), however unnecessarily long dead-times are leading to increased conduction losses. Furthermore, in resonant converters a low turn-off current is favorable leading the focus on optimal dead-time. In this paper it is qualified how the dead-time resolution in Field Programmable Gate Array (FPGA) controlled converters can be increased and how it effects the diode losses during the dead-time.