Analytical design model for epitaxial bipolar power transistor switches

Abstract

Continuous improvement in .the field of technology and transistor physics have progressively opened up, to bipolar devices, the area of power applications upto 50 or 100 KVA. In particular the control of deep diffusion and thick epitaxies with low impurity concentrations had led to use n+pn-n+ bipolar transistor as power switches. In this thesis an analytic design model is developed for epitaxial bipolar transistor swi tches where optimal calculations have been carried out for structural parameters which make it possible to comply in the best possible way with given specifications. All the numerical models follow a lengthy procedure and involves a large amount of computations. On the other hand this model is simple and straight forward and needs less computations. Results obtained by using this analytic model are compared with those evaluated numerically and are found in good agreement.