Direct Drive D-Mode GaN HEMT Switching Characteristics and Turn-off Loss Reductions

• Published in: IEEE transactions on power electronics pp. 1 - 11
• Main Authors: Lai, Jih-Sheng, Hsieh, Hsin-Che, Liu, Ching-Yao, Chieng, Wei-Hua, Yang, Chih-Yi, Hsu, Johnny, Chang, Edward Yi
• Format: Journal Article
• Language: English
• Published: IEEE 11-11-2024
• Subjects: Charge pumps; d-mode GaN HEMT; Direct drive; DPT; Gallium nitride; Gate driving; HEMTs; Logic gates; modified cascode; MOSFET; normally off; normally on; Pins; Silicon; Switches; Threshold voltage; Wire
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2024.3496672

This paper aims to evaluate the depletion-mode gallium nitride high electron mobility transistor (d-mode GaN HEMT) using direct-drive gating and double-pulse-test (DPT) to assess switching energy. The gate driving circuit features a modified cascode structure for 'normally off' operation and a charge-pump circuit to supply a negative gate voltage for turn-off operation. This paper described these features theoretically and validated with experimental results. Similar to enhancement-mode (e-mode) power MOSFETs or HEMTs, adjusting the gate drive resistance can affect the switching speed and associated losses, but the d-mode GaN HEMTs present an additional feature with turn-off loss reduction through gate voltage control. Thus, the main contribution of this paper is to propose and demonstrate significant turn-off loss reduction using the direct-drive approach for d-mode GaN HEMTs.