A GaN HEMT Short-Circuit Protection Circuit With Adaptive Blanking Time Generation Based on $dV_{\text{DS}}/dt$ Detection

Short-circuit protection (SCP) of gallium nitride high electron mobility transistors (GaN HEMTs) is critical to the reliability of power electronic systems. The conventional desaturation-based SCP method requires a properly configured blanking time. If the blanking time is too long, the power loss of the GaN HEMT increases during a short-circuit (SC) event. Conversely, if it is too short, false triggering of SCP may occur. To address this issue, an adaptive blanking time generation circuit is proposed. The blanking time is determined by detecting dVDS/dt, which enables adaptive activation or deactivation of VDS monitoring. With the 650 V/30 A GaN HEMT, the proposed method is validated on the laboratory test bench. Experimental results verify that effective protection is achieved under both hard switching fault (HSF) and fault under load (FUL) conditions by the proposed method. The results show that the total SCP time of the proposed method is 130 ns during HSF and 66 ns during FUL.