Aziz Ahmed, Ian Kennedy, and Keith Heppenstall
Philips Semiconductors

The trend toward higher power density requires greater attention to heat transfer for the device to stay within its area of safe operation. Thermal limitations have always been posing constraints on the reliability of power semiconductor devices. Manufacturers can provide simulation models that can imitate the operation of a device in actual circuits. This paper presents a Pspice model for a MOSFET where there is a link between the electrical and thermal equivalent models of the device. The proposed model incorporates the self-heating of the MOSFET that modifies the electrical characteristics of the device depending on the junction temperature. The proposed model has been validated by lab measurements.