Silicon carbide merged PiN Schottky diode switching characteristics and evaluation for power supply applications

A newly developed silicon carbide (SiC) merged PiN Schottky (MPS) diode combines the best features of both Schottky and PiN diodes to obtain low on-state voltage drop, low leakage in the off-state, fast switching, and good high temperature characteristics. In this paper, the switching characteristics of 1500 V, 0.5 A rated SiC MPS diodes are evaluated and compared to the fastest, similarly rated silicon diodes available. Experimental results indicate that the reverse recovery time and associated losses are nearly zero for the SiC MPS diodes. By replacing the best silicon diodes available with a SiC MPS diode, the efficiency of a test-case power supply was found to increase from 89% to 91.5% for switching at 100 kHz, and from 82 % to 88% at 186 kHz. A significant electromagnetic interference (EMI) reduction was also obtained with the SiC MPS diodes compared to the silicon diodes for the noise spectrum range from 70 MHz to 150 MHz.