This paper examines dynamic Temperature Sensitive Electrical Parameters (TSEPs) for SiC MOSFETs. It is shown that the output current switching rate (dIDS/dt) coupled with the gate current plateau (IGP) during turn-ON would be the most effective under specific operating conditions. Both parameters increase with the junction temperature of the device as a result of the negative temperature coefficient of the threshold voltage. The temperature dependency of dIDS/dt has been shown to increase with the device current rating (due to larger input capacitance) and external gate resistance (RGEXT). However, as dIDS/dt is increased by using a small RGEXT, parasitic inductance suppresses the temperature sensitivity of the drain and gate current transients by reducing the “effective gate voltage” on the device. Since the temperature sensitivity of dIDS/dt is at the highest with maximum RGEXT, there is a penalty from higher switching losses when this method is used in real time for junction temperature sensing. This paper investigates and models the temperature dependency of the gate and drain current transients as well as the compromise between the increased switching loss and the potential to implement effective condition monitoring using the evaluated TSEPs.ud
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