Integrated-Circuit Transistor and Diode Models for Network-Analysis Programs

A set of new models of varying complexity and accuracy is derived for the large-signal transient behavior of bipolar transistor and diode structures found in integrated circuits. The derivation starts with the defining equations of the so-called nonlinear model for the four-layer integrated-circuit transistor and proceeds by reformulating several terms in these equations to remove, in effect, current sources in the symbolic model dependent on the complex frequency variable The removal of this dependence yields models containing resistors, capacitors, and nonfrequency-dependent sources. With the availability of these models, network-analysis programs unable to accommodate frequency-dependent sources become directly applicable to the computation of the large-signal transient behavior of bipolar integrated circuits. Considerations pertaining to practical application guide the choice of approximations used in the derivation. The limits of validity of these approximations and of others that set the range of validity of the resulting models receive careful attention.