GENERAL STRUCTURE OF INTEGRATOR-BASED CONTINUOUS-TIME ACTIVE-RC FILTER AND APPLICATIONS

Abstract

In the paper, a general structure of integrator-based continuous-time Active-RC filter is presented. More specifically, filter structures containing inverting amplifiers and passive feedback network are considered. The structure is analyzed using matrix description. The extensions of the model that take into account finite DC gain and finite bandwidth of operational amplifiers as well as other non-ideal effects are presented. The matrix-based approach is formulated especially for efficient use in computer analysis and design of Active-RC filters. An application example of the proposed approach to obtain OPAMP specifications for 3rd order low-pass Chebyshev filter for Analog Front End for VDSL is given. In this paper, we consider a general Active-RC filter topology suitable for computer-aided analysis, design and optimization of Active-RC filters. The structure is not the most general one, since it is restricted to filter topologies containing only inverting amplifiers (especially integrators) and RC feedback network.