Multi-section model of an N+-P-v-N+ high voltage power switching transistor

An improved model is introduced to represent NN⁺-P-v-N⁺ high-voltage power switching transistors. This model differs from the conventional Ebers-Moll model in three major respects: (1) a non-linear collector resistance is included to account for conductivity modulation in the collector region; (2) the forward current gain is made to depend on V_CE as well as I_c so as to account for the Early effect; (3) a multisection network representation of the ambipolar diffusion equation is used to account for the effects of stored charge in the collector region particularly when the device operates in the quasi-saturation condition. The correlation of this model with observed D.C. and switching behavior is notably better than that of the Ebers-Moll model.