Study on High Frequency Limitation of SJ-MOSFET/SiC-SBD pair in Comparison with Normal MOSFET/SiC-SBD pair

High frequency limitation of a SJ-MOSFET/SiC-SBD pair compared with a normal MOSFET/SiC-SBD pair under real circuit conditions is investigated. Power losses of the SJ-and normal MOSFETs, which determine the maximum switching frequency, are calculated with a circuit power loss model for unipolar devices. Power loss calculation results reveal that the switching loss energy of the SJ-MOSFET is larger than that of the normal MOSFET under the same chip size and same circuit parameters. Due to the lower specific on resistance of the SJ-MOSFET, the total power loss of the SJ-MOSFET is lower than that of the normal MOSFET in the switching frequency range below 1 MHz. The maximum switching frequency depends on circuit stray inductances drastically.