Investigation of the MHz switching frequency PFC converter based on high-voltage GaN HEMT

Abstract

In this paper, the significant impact of MHz switching frequency operation is demonstrated as effectively size reduction of boost inductor in the Continuous Conduction Mode (CCM) power factor correction (PFC) converter. To maintain high efficiency at MHz switching frequency, the gallium nitride high electron mobility transistor (GaN HEMT) is used to take place of the conventional silicon MOSFET in the 300W/1MHz CCM boost PFC converter. The experimental results validate the advantages of the GaN HEMT over the CoolMOS, achieving full load efficiency improvement of 1.2% and 2.1% respectively at 230VAC and 115VAC input condition. The detailed loss breakdown indicates that the GaN HEMT could reduce the switching loss substantially, the main loss under MHz PFC operation, so as to achieve efficiency improvement.