Gummel-Poon Model Parameter Optimization for a Power Transistor

Computer Aided Design and Analysis tools rely heavily on accurate device models. The development of an accurate PNP power transistor model is presented in this paper. The device is modeled in terms of the Gummel-Poon model. It is difficult to obtain accurate values for the parameters due to the complexity of the model and the inherent assumptions and inaccuracies in the measurement procedure. Optimizing the parameter values through trial and error is not easy and a more systematic and efficient method is presented. An interactive design optimization program called DESIGN is used to adjust the parameter values so that the measured and the predicted output characteristics match at selected values of base current. The result is an accurate model that is sophisticated enough to predict the complex behavior of the transistor.