Modified charge-control equation for more realistic simulation of power diode characteristics

The mathematical diode model currently used in most circuit simulations is not able to fully account for the device's forward and reverse recovery characteristics. This is due to the quasi-static diffusion charge equation and the fixed internal resistance used in the model. A proposed modification to the charge equation is presented in this paper. This important modification, together with a proposed charge-dependent internal resistance equation, have been test-implemented in PSpice using the Analog Behavioral Modeling technique. It has been experimentally verified that the new model is able to describe the power diode forward and reverse recovery behaviour more realistically without degrading the convergence properties of the simulators.