Prethreshold Voltage as a Low-Component Count Temperature Sensitive Electrical Parameter Without Self-Heating

Temperature sensitive electrical parameters (TSEPs) are promising for measurement of the insulated gate bipolar transistor (IGBT) junction temperature. Many TSEPs have been proposed in the literature and most require current sensors, and convoluted hardware and data processing, which are associated with increased complexity and cost. In this letter, a new TSEP is proposed called prethreshold TSEP, VGE(pre-th). VGE(pre-th)requires only a voltage sensor and a counter. Besides less hardware requirement, VGE(pre-th)does not suffer from self-heating-a problem that most TSEPs encounter. This letter presents the operation of VGE(pre-th)with the help of simulation. Experimental tests on a 3.3 kV, 800 A IGBT were conducted to characterize VGE(pre-th). It is shown that the new TSEP proposed has a sensitivity of -2.2 mV/°C.