An Active Clamped Resonant Ultra-High Frequency Quasi-Square Wave Gate Driver for SiC MOSFET

The SiC MOSFETs are hard to be driven at MHz due to their large gate capacitances, this paper presents an active-clamped resonant high-frequency quasi-square-wave driver circuit which can drive SiC MOSFETs in MHz switching power amplifiers. The proposed driver can operate over a wide frequency range and duty cycle range as its parameters do not need to be modified according to resonant switching frequency. And it has ns-level rise/decline time with the use of high frequency resonant network, which means no deviation in the output duty cycle. Meanwhile, the clamp structure of the proposed circuit can reduce the sensitivity of the high-frequency driver to parasitic parameters, and has a strong anti-interference capability. Finally, a prototype of the proposed active clamped resonant gate drive (RGD) and a Class-E RGD were built and applied to drive a 13.56MHz/1.5kW Class-E power amplifier for comparison. The experimental results strongly demonstrate the advantages of the proposed driver. The proposed driver can drive SiC MOSFET in quasi-square-wave over 6.78~20.12 MHz, with a duty cycle of 35%~65% and t<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</inf>/t<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</inf> about 3.9~6.2 ns. And it improves the efficiency of the Class-E power amplifiers from 84% to 87% comparing with the Class-E RGD.