ABSTRACT
In this section we will consider the design of second-order sections that incorporate a single operational amplifier. Such designs are based upon one of the earliest approaches to RC active filter synthesis, which has proven to be a fundamentally sound technique for over 30 years. Furthermore, this basic topology has formed the basis for designs as technology has evolved from discrete component assemblies to monolithic realizations. Hence, the circuits presented here truly represent reliable well-tested building blocks for sections of modest selectivity.
