Study on advanced power device performance under real circuit conditions with an exact power loss simulator

Power losses of 700V 2.7mOmegacm² SiC-MOSFETs including influences of circuit stray inductances have been investigated with an originally developed circuit power loss simulator. The device parameters of the SiC-MOSFETs for the power loss calculation are extracted from a SiC-IEMOSFET fabricated at AIST PERC. The power losses of three types of chip areas are investigated and compared to power loss of a CoolMOS. The switching loss energies of the SiC-MOSFETs are larger than that of the CoolMOS in the same circuit conditions. The maximum switching frequencies of the SiC-MOSFETs are 1/2 ~ 2/3 times lower than that of the CoolMOS. Based on total circuit power loss calculation results, heatsink volumes for a half bridge type DC-DC converter at 200kHz operation are estimated. In the case of the SiC- MOSFET3(smallest chip size)/SiC-SBD pair, the heatsink volume can be reduced to about 45% compared to the CoolMOS/SiC-SBD pair due to the T_j=200degC operation and the lower circuit power loss.