Some New Configurations for Active Filters

Abstract

Some new active-filter configurations based on the pole-zero cancellation technique are introduced. First, for the range Q ≤ 50 a single-amplifier circuit is suggested. For higher selectivity (50 < Q ≤ 500) a two-amplifier circuit is proposed. Another easily cascadable two-amplifier circuit with a reduced number of capacitors is discussed. In the latter case the filter function is determined by certain resistive ratios. All the configurations proposed employ integrated circuit operational amplifiers (OAs). The sensitivity problem is discussed in detail. Effects of the finite OA frequency response are also investigated. © 1972, IEEE. All rights reserved.