A moving boundary diffusion model for PIN diodes

A large number of diode models exist that simulate the reverse recovery process. Many models assume an abrupt change of current during reverse recovery. Some models were verified by calculating the diode's response after the application of a step forcing voltage. Only a few models described in the literature compare simulation results with experimental data. The abrupt change in current calculated by most diode models will ensure large di/dt, which in turn will result in the calculation of an excessive voltage spike. The diode model described in this paper is aimed at the application of high power rectification where the exciting voltage is more likely to be sinusoidal rather than a step change. The formulation is particularly useful in modeling very high power systems such as electromagnetic launch systems where calculation speed and accuracy of results are held at a premium. The model is formulated based on a p+in+ type diode. In addition, by considering the fact that the width of the intrinsic bulk region reduces significantly during the reverse biased condition, the model will more accurately calculate reverse recovery current and voltage. Finally, the model is verified by comparing simulation results to experimental data.