A simple switching loss model for buck voltage regulators with current source drive

A review of switching loss mechanisms for synchronous buck voltage regulators is presented. Following the review, a new simple analytical switching loss model is proposed for voltage regulators with current source drive. The model includes the impact of common source inductance and parasitic inductance on switching loss. It uses simple equations to calculate the rise and fall times and piecewise linear approximations of the MOSFET voltage and current waveforms to allow quick and accurate calculation of switching loss. Spice is used to demonstrate the accuracy of the model operating in a 1MHz synchronous buck voltage regulator at 12V input, 1.3V output. Experimental results are presented to demonstrate the accuracy of the proposed model.