Spice-aided modelling of the UC3842 current mode PWM controller with selfheating taken into account

This paper deals with the problem of modelling current mode PWM controllers with the use of SPICE. The monolithic integrated circuit UC3842 is considered in the paper. Two isothermal models of UC3842 known in the literature are compared, tested and discussed. A new electrothermal model (ETM), including selfheating, of the considered controller is proposed and described in detail. The experimental verification of the ETM showed its much greater accuracy compared to the isothermal models of the investigated device.