MOSFETs under short circuit conditions for aeronautical applications

The short circuit performance of silicon carbide MOSFETs has been evaluated in a 270 V system designed to mimic the characteristics of a commercial airliner power system. The devices demonstrated the ability to withstand being short–circuited for a period of 8 µs before suffering a catastrophic failure when that coincided with the turn–off transient for a 9 µs pulse. At the point of turn off the junction temperature in the transistor is calculated to have risen to approximately 950 °C. The withstand period for a transistor held at a case temperature of 150 °C was 7 µs, indicating the failure is of a thermal origin and this reduction needs to be addressed for devices operating in high temperature environments, such as those found in aerospace.