A Desaturation-based High-speed Overcurrent Detection Gate Driver with High Noise Immunity for GaN HEMTs Power Semiconductor

Abstract

Nowadays, more and more power converters are using wide band gap (WBG) power semiconductors because of their excellent performance. And overcurrent detection is a fundamental function of most power converter. Above all, a desaturation-based detection method is preferred because it is easy to implement. However, there is a false triggering issue caused by dv/dt noise of Device under test (DUT). In this article, two kinds of overcurrent detection circuit based on desaturation are proposed, and performance comparison with existing desaturation detection circuit is made. In this paper, the normal operation of DUT and the two cases of arm-short are discussed. In addition, this paper uses LTspice to simulate the waveforms of the simulation results and the principle of circuit operation. The simulation results show that the proposed circuit ensures that the margin is above 4 V at normal on, and that the DUT is triggered within 200 ns when arm-short occurs and turn DUT off for protection.