High switching frequencies are among the biggest enablers for small size. To that end, gallium nitride (GaN) switches provide an effective way to achieve these high frequencies given their low parasitic output capacitance (C OSS ) and rapid turn-on and turn-off times. It is possible, however, to amplify the high-power densities enabled by GaN switches through the use of advanced control techniques.

In this article, I will examine an advanced control method used inside a 5-kW power factor corrector (PFC) for a server. The design uses high-performance GaN FETs to operate the power supplies at the highest practical frequency. The power supply also uses a novel control technology that extracts more performance out of the GaN FETs. The end result is a high-efficiency, small-form-factor design with higher power density.

系統概況

眾所周知，圖騰柱PFC是高功率、高效率PFC的主力。圖1展示了拓撲結構。

基本圖騰柱PFC拓撲，其中1和S2是高頻GaN開關和3和S4是低頻開關硅MOSFETs

圖1基本圖騰柱PFC拓撲，其中1和S2是高頻GaN開關和3和S4是低頻開關硅MOSFETs。來源:德州儀器

使用GaN和前述算法的兩相5 kW設計示例的照片。

*附件：使用先進的控制方法提高GaN基PFC的功率密度.pdf