IGBT junction temperature measurement via combined TSEPs with collector current impact elimination

Junction temperature of insulated gate bipolar transistors (IGBTs) plays an important role in power semiconductor devices reliability. However, it is difficult to have direct access to the chip to obtain the junction temperature. This paper provides a new approach to extract the junction temperature by using combined thermo-sensitive electric parameters (TSEPs) during turn-off transient due to the parasitic inductor LeE. The turn-off delay time (tdoff) and voltage peak of LeE during turn of transient (VeEPeak) can both serve as TSEP for their temperature dependence. High linearity is inherited when the two TSEPs are combined to extract the junction temperature. The proposed method has the clear advantages of simple realization compared with individual TSEP to obtain junction temperature because it eliminates the influence of collector current (7c). Experiments have been implemented to evaluate the effectiveness of the proposed solution.