A full dynamic model for pn-junction diode switching transients

A new model is presented for the dynamics of a pn-junction diode that is based upon an exact Green´s function solution to the minority-carrier diffusion equation. The model provides a more accurate solution for large-signal switching transients, particularly during the reverse recovery phase, and it produces the correct storage time and high frequency admittance behavior, both of which are incorrectly predicted by the commonly-used charge-control models. No assumptions on the terminal voltage or current waveforms are made, so the model remains valid under any circuit conditions. In addition, the model is conceptually and mathematically very simple, while it fully represents the distributed nature of the stored minority-carrier charge. This new model also easily illustrates the limitations on lumped, charge-control models of the pn-junction