An electrical model of a NPT-IGBT including transient temperature effects realized with PSpice device equations modeling

To describe the electrical and thermal behaviour of an insulated gate bipolar transistor (IGBT) for circuit simulation, an analytical model is designed. The model uses a charge-control approach according to the HEFNER model. The effect of the transient chip-temperature on different physical parameters is defined by the thermal model. The numerical realization is made on the basis of nodal analysis and a linearization according to the Newton-Raphson method. All equations are implemented in C-code and combined with the simulator source code, using the PSpice device equation option. As a result, an internal model is created. Due to the thermal network, the IGBT has become a four terminal device. It can be applied to various thermal and electrical circuit topologies. A transient simulation of the device temperature allows short circuit or overload conditions to be studied in detail.