ABSTRACT
This chapter presents the basic but widely used bipolar junction transistor (BJT) compact models for circuit computer-aided design (CAD). BJTs are very often used in very-large-scale-integratedcircuits. The basic Ebers–Moll (EM1) model is fairly accurate only for modeling the DC characteristics of BJTs at any ambient temperature. The enhanced BJT model includes parasitic elements in BJT structure to improve DC modeling accuracy and offers capability for transient analysis. The complete set of BJT-model parameters consists of basic dc parameters, EM2 model parameters for parasitic elements, space-charge layer recombination model parameters, and the unified integrated charge control model parameters describing the base-width modulation and high-level injection. In order to develop a complete BJT model for circuit CAD, first develop the basic DC model using the EM formulation and then include the different parasitic elements of the BJT structure and physical effects.
