A Fast Short-Circuit Protection Method for Ohmic gate P-GaN HEMT Based on Gate Charge

GaN HEMT devices exhibit lower short-circuit capability, posing significant risks in practical applications. This paper presents a fast short circuit (SC) protection circuit for ohmic gate P-GaN HEMT under hard-switch fault (HSF) condition and fault under load (FUL) condition, based on the gate charge characteristics. The proposed SC protection technique utilizes gate current integration to measure gate charge, enabling the detection of SC faults in the device. Experimental results demonstrate that the proposed method allows the SC protection circuit to detect HSF or FUL SC fault events within 50 ns and to shuts down the GaN HEMT device within 150 ns, offering rapid and reliable protection against short-circuit faults.