Switching losses in a 1.7 kW GaN based full-bridge DC-DC converter with synchronous rectification

The paper presents the detailed analysis of switching losses in GaN devices for an isolated full-bridge dc-dc converter. Switching losses includes capacitive losses along with turn-on and turn-off losses of the power MOSFET. In hard switched converters, the output capacitance of MOSFET contributes to a significant part of the switching loss. The capacitive loss analysis also helps in determining the optimum number of devices used in parallel for a given power level and switching frequency. The analysis is performed on a 1.7 kW full bridge isolated dc-dc GaN converter at a switching frequency of 50 kHz. The paper also presents the GaN switch efficiency curve for an isolated dc-dc GaN converter with different number of devices in parallel.