10 kW High Efficiency Compact GaN-Based DC/DC Converter Design

Gallium-nitride (GaN) high-electron-mobility transistors (HEMTs) have shown their distinct advantages over silicon devices in the power converter design, including high switching speed, no reverse recovery loss, high switching frequency and compact package. This helps to build a high-efficiency and high-power-density 10 kW LLC resonant converter. A switching cell with two paralleled 650V 60A enhanced-mode GaN HEMTs are proposed first, including the layout consideration and thermal management. The switching cell is adopted at the primary and secondary side separately in the converter. An integrated high frequency litz-wire transformer is presented with its optimization process. With the 3D package of the converter structure using the GaN-based switching cell and the litz-wire transformer, the converter achieves 97.9% peak efficiency under full power and 131 W/in
³
(8 kW/L) power density.