Wave digital filter modeling of circuits with operational amplifiers

Abstract

We extend the Wave Digital Filter (WDF) approach to simulate reference circuits that involve operational amplifiers (op-amps). We handle both nullor-based ideal op-amp models and controlled-source-based linear op-amp macromodels in circuits with arbitrary topologies using recent derivations for complicated scattering matrices. The presented methods greatly increase the class of appropriate circuits for virtual analog modeling, and readily extend to circuits with any number of op-amps. Although op-amps are essential to many circuits and deviations from ideal can be important, previous WDF research applies only to the limited case of circuits with ideal op-amps, in differential amplifier topology, with no global feedback.