A simple method of incorporating amplifier imperfections inRC-active filter designs

Abstract

A novel technique is introduced for improving the design of second-order active filter circuits with the aid of an analogue circuit analysis program. Using SPICE-compatible macromodels, all relevant non-ideal amplifier parameters can be considered during the design process. The principle of the method is to fine tune the pole of the transfer function by modifying a suitable part of the filter network, thereby improving the accuracy of the filter response and extending the usable frequency range considerably. Based on the proposed method a simple step-by-step procedure is given, which is illustrated by a specific low-pass example using the network analysis package PSpice/Probe.