347 / 2017-12-09 02:53:48

300W 175°C half bridge power building block with SiC MOSFETs for harsh environment applications

全体主题 > Harsh environment (e.g. high temperature) operation and reliability

A 300W 175oC half bridge power building block with SiC MOSFETs is investigated for high temperature harsh environment applications. The switching energy of 1.2kV SiC MOSFET CHT-NEPTUNE with TO-257 package and 225oC junction temperature from Cissoid are characterized at both room temperature and high temperature. 650V SiC diode 1N8032 with TO-257 package and 250oC junction temperature from GeneSiC is used as the freewheeling diode for double pulse switching energy test. The Turn-on loss of SiC MOSFETs is larger than the turn-off loss. The turn-on loss gets lower when the junction temperature increase, and the turn-off loss gets higher when the junction temperature increase. A half bridge power building block prototype is built in lab to verify the power capability at 175oC high temperature. The power loss and temperature rise of SiC MOSFET are comparative studied at different switching frequency for the half bridge power building block. Higher switching frequency will lead to significant temperature rise for SiC MOSFET from 20kHz to 50kHz at 175oC high temperature. The temperature rise and the volume of passive components need to be optimal trade-off at high temperature.