Exact synthesis with real amplifiers

Abstract

Second-degree active filter circuits are synthesized with operational amplifiers having a single pole or two poles and one zero. The method is applied to obtain designs and sensitivities for six useful filter sections. It is shown 1) that the two-pole amplifier is sometimes not the better choice, even though it has more gain at the operating frequency, and 2) that sensitivities are optimized by tradeoffs involving positive feedback.