A new electrothermal compact model of the current mode pulse width modulation controller—UCC3800—dedicated for SPICE is proposed in this paper. The form of this model is presented and described in detail. The results of the experimental verification of the model are also presented for the device operating in the test circuit. It is shown that self-heating influences essentially the characteristics of the considered device and the proposed model is of good accuracy. Copyright © 2011 John Wiley & Sons, Ltd.