Compact SEPIC converter using a GaN HEMT

The increasing demand for miniaturization in electronic devices has driven the design of compact power supplies which operate at higher switching frequencies. Gallium-nitride semiconductor switching devices are very promising for increasing the power density and efficiency of switch-mode power converters due to their high switching speed and low on-resistance relative to silicon devices. In this paper we describe a simple SEPIC converter using a normally-off hybrid GaN-on-Si cascode switch. Operating with a switching frequency around 1.5MHz, and with 100W load, the compact circuit was measured to have a conversion efficiency of 94.25%.