Highly Reliable Short-Circuit Protection Circuits for Gallium Nitride High-Electron-Mobility Transistors

Abstract

This paper presents a circuit for detecting and protecting against short circuits in E-mode gallium nitride high-electron-mobility transistors (GaN HEMTs) and analyzes the protection performance of the circuit. GaN HEMTs possess fast switching characteristics that enable high efficiency and power density in power conversion devices. However, these characteristics also pose challenges in protecting against short circuits and overcurrent situations. The proposed method detects short-circuit events by monitoring an instantaneous drop in the DC bus voltage of a circuit with GaN HEMTs applied and uses a bandpass filter to prevent the malfunction of the short-circuit protection circuit during normal switching and ensure highly reliable operation. Using this method, the short-circuit detection time of E-mode GaN HEMTs can be reduced to 257 ns, successfully protecting the device without malfunctions even in severe short-circuit situations occurring at high DC link voltages.