Compact model of power MOSFET with temperature dependent Cauer RC network for more accurate thermal simulations

• More precise but still simple SPICE like model of the power MOSFET is presented.
• Results prove the importance of temperature dependent resistors in the thermal network.
• Importance and correctness of added buried heat source is shown.
• Model is able to simulate destruction of the device during UIS with very good accuracy.
• Comparison with analytical models was done and better accuracy was observed.

A new, more accurate SPICE-like model of a power MOSFET containing a temperature dependent thermal network is described. The designed electro-thermal MOSFET model consists of several parts which represent different transistor behavior under different conditions such as reverse bias, avalanche breakdown and others. The designed model is able to simulate destruction of the device as thermal runaway and/or overcurrent destruction during the switching process of a wide variety of inductive loads. Modified thermal equivalent circuit diagrams were designed taking into account temperature dependence of thermal resistivity. The potential and limitations of the new models are presented and analyzed. The new model is compared with the standard and empirical models and brings a higher accuracy for rapid heating pulses. An unclamped inductive switching (UIS) test as a stressful condition was used to verify the proper behavior of the designed MOSFET model.