Switching performance characterization of SiC Schottky diodes in switch-mode DC-DC converters

The SiC Schottky diode, with its high blocking voltage capability, absence of reverse recovery, and negligible temperature dependence on switching behavior, is suitable for most power electronics applications especially in circuits that demand high efficiency and high switching frequencies. Recent studies dealing with the comparison of SiC Schottky with ultra-fast diodes are application-specific and they do not quantify the contribution of the superior switching performance of the SiC Schottky to the improvement of the switch-mode converter´s efficiency. To address this deficiency, we compare the performances of the D12S60 SiC Schottky diode to leading ultra-fast diodes of comparable rating, such as the STTA1206D, in hard-switching buck and buck-boost switching converters. Our study includes the measurement of the diode and FET switching and conduction losses as well as converter efficiency while varying the input voltage, load current, and switching frequency.