Performance comparison of a 650 V GaN SSFET and CoolMOS

The new technology of wide band gap semiconductors is said to outperform up-to-date silicon devices. High voltage Gallium Nitride (GaN) transistors, now emerging in the market, have even three times shorter switching times and even four times smaller energy losses compared to the best in-class Si devices. In this paper the performance of a 650 V GaN SSFET is evaluated and compared with the newest silicon family of CoolMOS™ technology. Switching times of transistors are measured in a double-pulse test. Moreover, a prototype buck converter is built with two kinds of transistors. In this setup efficiencies are experimentally measured and compared. It is proved that application with SSFETs allows ease of operation and reduced power losses. Finally, the benefits of achieving high switching frequency (500 kHz) when it comes to a reduction of an inductor in an output filter are described.