SPICE aided estimation of the power BJT model parameters

This paper concerns the problems of estimation of SPICE DC built-in BJT model parameters. PARTS software, called in this paper the estimation parts algorithm (EPA), is intended for this purpose. The coordinates of some initial points lying on the selected DC characteristics, are needed for EPA as the input data. In the paper the shortcomings and disadvantages of PARTS are discussed. Above all, the strong influence of the selection of the number and the position of initial points on the estimated parameter values set is investigated. To improve the estimation procedure, the modified estimation algorithm (MEA) worked out by the authors, based on PARTS software is proposed. MEA enables getting the proper values of parameters, also those parameters, which are not considered and calculated by PARTS. The correctness of MEA was verified experimentally by comparison of the selected DC characteristics of the power BJTs received from measurements and the analog characteristics calculated by SPICE with the parameter values obtained from MEA.