ABSTRACT
This chapter provides a tutorial presentation of nonlinear transistor modeling. After reviewing the types of models, it focuses on equivalent circuit models, of the type used in SPICE. The chapter describes improvements in models and discusses the modeling of temperature effects and the effects of traps. It also describes parameter extraction and model verification. The physics-based model would be constructed with all known parameters and simulations of current control for DC and transient or radio frequency operation, and then compared with measured data. The usual approach to verification of a large-signal model is to compare measured device performance with simulations under the same conditions. The chapter is concerned with equivalent circuit models because they are formulated to be efficiently exercised in a circuit simulator, and thus are efficient for circuit design and optimization. The transistor model with such circuits may then be used to determine if the lag effects interfere with proper operation of the circuit.
