Comparison of body diode switching characteristics of 650V power devices

Abstract

The body diode characteristics at high di/dt (approximately 2000A/µs) were evaluated for four power devices with a breakdown voltage of 650V: (1) GaN-FET (cascode), (2) SiC-MOSFET, (3) Si-SJ-MOSFET, and (4) Si-RC-IGBT. The Qrr of the GaN-FET and SiC-MOSFET were approximately 6.3% and 4.5% of that of the SJ-MOSFET, respectively. The GaN-FET has a cascode-connected Si-MOSFET body diode. The accumulation of minority carriers in this diode was small, and the main component of the recovery current was due to the parasitic capacitance of the device. In addition, in the IGBT, a dynamic avalanche occurred and a second peak appeared in the recovery current.