Using gallium-nitride cascode switching devices for common mode electromagnetic interference reduction in power converters/inverters

The gallium-nitride (GaN) cascode switch has received much attention recently for line-operated medium–high frequency (200 to 500 kHz) medium-power (200–1000 W) applications. Owing to its device structure, there are two TO-220 package options available with regard to the tab internal connection, unlike the conventional vertical power MOSFET. It is pointed out in this study that using proper package combination of GaN cascode devices, the electromagnetic interferences can be reduced in power converters/inverters. A 240 W 200 kHz LLC power converter with a front-end power-factor-correction circuit was built for experimental verification of the theory. Significant reduction was observed. Same theory can be applied to other converter/inverter configurations.