Electrical design considerations for a 4 kW buck converter with normally-off GaN devices at a Dc-link voltage of 400 V

GaN power semiconductor devices show promising properties to achieve high power densities in power converters for voltages in the range of 400 V. The utilization of high switching frequencies and high switching speeds are particularly challenging for filter design and the circuit layout. Within this paper, a comprehensive analysis of design considerations for a GaN based synchronous buck converter is presented to achieve a transferred power of 4 kW at a dc-link voltage of 400 V and a switching frequency of 400 kHz. This analysis comprises the evaluation of the high-frequency performance of dc-link capacitors and impacts of parasitics in the commutation cell.