Comparison of Total Losses of 1.2 kV SiC JFET and BJT in DC-DC Converter Including Gate Driver
The 1.2 kV SiC JFET and BJT devices have been investigated and compared with respect to total losses including the gate driver losses in a DC-DC converter configuration. The buried grid, Normally-on JFET devices with threshold voltage of -50 V and -10V are compared to BJT devices with ideal semiconductor and passivating insulator interface and an interface with surface recombination velocity of 4.5•104 cm/s yielding agreement to the reported experimental current gain values. The conduction losses of both types of devices are independent of the switching frequency while the switching losses are proportional to the switching frequency. The driver losses are proportional to the switching frequency in the JFET case but to a large extent independent of the switching frequency in the BJT case. The passivation of the emitter junction modeled here by surface recombination velocity has a significant impact on conduction losses and gate driver losses in the investigated BJT devices.
Edouard V. Monakhov, Tamás Hornos and Bengt. G. Svensson
J. K. Lim et al., "Comparison of Total Losses of 1.2 kV SiC JFET and BJT in DC-DC Converter Including Gate Driver", Materials Science Forum, Vols. 679-680, pp. 649-652, 2011