Co-extraction method for DC model parameters of BJT based on global optimization and physical analysis

Based on the SPICE BJT models, a new co-extraction method for DC model parameters of BJT is proposed. From measured terminal characteristics data of BJT, the Model Editor, a model parameters extraction tool provided by PSpice, uses group extraction method to obtain DC model parameter values. But, actual situations show that there is a large error between the output characteristics determined by the model parameters extracted by Model Editor and the measured output characteristics. In order to obtain the most optimal values, it is necessary to use Optimizer tool to furthermore globally optimize for all the DC model parameters from parts of results of Model editor. And because the selection of initial values is important to optimization results, based on the physical processes of BJT, most DC model parameters close to the most optimal values are calculated as the initial values of optimization. Thus, the new co-extraction method improves extraction accuracy and efficiency without introducing complex mathematic optimization arithmetic.