Short-Circuit Operation of a 650-V/60-A GaN-Based Half-Bridge

The Short-Circuit (SC) robustness of GaN HEMTs represents a relevant issue for their use in power electronics. The research only focused on type I SC behavior of the single GaN transistor, in addition using large gate resistors during experimental tests. Here, we investigate the real case of a GaN-based Half-Bridge operating in SC conditions, focusing on the impact that another identical device can have on the SC. After designing and realizing a prototype test board with two 650-V/60-A GaN HEMTs, experimental SC tests confirm the theoretical analysis and highlight the effects of the DC-link voltage, demonstrating that both the presence of a second device and the use of large gate resistor can strongly alter the expected SC behavior.