Temperature Monitoring of Multi-Chip SiC MOSFET Modules: On-Chip RTDs vs. VSD(T)

In this paper we compare on-chip RTD sensors and the V
SD
(T) method for temperature measurement of multi-chip SiC MOSFET modules. We find that the average temperature across multiple chips measured via on-chip RTDs correlates closely with the V
SD
(T). However, the minimum and maximum chip temperature changes according to the module’s operating conditions. This cannot be detected by the V
SD
(T) method. In a half-bridge module with 4-chips per switch position, we apply two operating conditions that give the same measured temperature via V
SD
(T). The maximum chip temperature, measured via the on-chip RTD, deviates over 5°C. This may have implications for power cycling lifetime on multi-chip power modules. We also demonstrate the use of the on-chip RTDs in an IGBT inverter.