Single-stage converter largely simplifies system architectures by achieving isolated AC/DC conversion with one converter stage. It eliminates many passive components from traditional 2-stage solution, therefore increases system power density and efficiency with reduced cost. This topology requires a bidirectional switch which can be simply and monolithically implemented by GaN technology on one die. The GaN bidirectional switch provides many advantages compared to the traditional back to back MOSFET implementation. This presentation showcases a 3.7kW single phase single stage converter for 400V EV charging, using CoolGaN bidirectional switch (BDS) to achieve better system performance. The GaN BDS device basics as well as single stage topology, operating principle and control algorithm with be introduced, supplemented by hardware demo and experimental result to verify the power density and efficiency advantage.
