A new electrothermal average model of the diode–transistor switch

In the paper a new electrothermal average model of the diode–transistor switch operating in any dc–dc converter is proposed. With the use of this model the non-isothermal characteristics of dc–dc converters in the steady-state can be obtained. The method of formulation of such a model and its structure are described in detail. The correctness of the elaborated model was verified by comparing the SPICE simulated characteristics of the buck and boost converters operating both in the continuous and discontinuous conducting mode, obtained by the electrothermal dc analysis with the proposed model and by the electrothermal transient analysis with the physical models of the diode and the transistor.