Thermal and electrical modelling of high power semiconductor devices

In spite of the substantial power handling capabilities of modern high power semiconductor devices the designer is often required to exploit them to their limits while at the same time ensuring that those limits are not exceeded. Since many of the power semiconductor performance ratings deteriorate with temperature, the ability to predict junction temperature variations during arbitrary current waveforms up to fault levels is essential for good design. To achieve this requires a computer model which combines the temperature-dependent electrical characteristics of the device with its thermal response when mounted on its heat sink. The authors present such a model which may be used not only for design studies but also, in real time as part of a control system for protection