High di/dt Switching Characteristics of a SiC Schottky Barrier Diode

Abstract

High di/dt switching characteristics of a commercially available silicon carbide schottky barrier diode (SiC-SBD) has been experimentally evaluated in the various di/dt values of 300 A/μs to 2500 A/μs range. Diode voltage waveforms, diode current waveforms, diode stored charges, and diode turn-off losses have been theoretically analyzed. The stored charge and the diode turn-off loss are independent of the forward current value, the di/dt value, and the junction temperature. It is shown that the switching behavior of the SiC-SBD can be expressed a simple variable capacitor, the capacitance of which depends on the reverse bias voltage. The switching characteristics of the SiC-SBD also have been compared to those of a commercially available ultra-fast silicon pn diode (Si-PND). The SiC-SBD has extremely low reverse current and low stored charge compared to those of the Si-PND. The SiC-SBD can reduce the IGBT turn-on loss compared to the Si-PND especially in the high di/dt operation.