Dynamic On-Resistance Characterization of GaN Power HEMTs Under Forward/Reverse Conduction Using Multigroup Double Pulse Test

In bridgeless power factor correction converters and inverters, GaN high-electron-mobility transistors (HEMTs) operate in both forward and reverse conduction modes, which may feature different dynamic on -resistance ( R _ON ) behaviors. Despite the extensive study of dynamic R _ON under forward conduction, dynamic R _ON under reverse conduction still demands comprehensive evaluation. In this letter, the dynamic R _ON of two commercial p-GaN gate HEMTs with different technologies under forward/reverse conduction and hard/soft switching is characterized using the custom-designed multigroup double pulse test system, which nearly eliminates the accumulated self-heating effect in the device. First, the test was conducted at off -state bias voltage = 400 V, I _DS = 70% I _DS(max) . For the Schottky-type p -GaN gate HEMTs, the dynamic R _ON in reverse conduction is found to be more than 3%–5% higher compared to the forward conduction. However, for the hybrid-drain-embedded gate injection transistor, operating in reverse conduction mode leads to a slighter dynamic R _ON degradation effect, with a reduction of approximately 10% compared to the forward conduction. Next, I _DS was modulated to evaluate its impact on dynamic R _ON . For both devices, during reverse conduction it was observed that the dynamic R _ON initially decreases and subsequently increases with the I _DS increase.