A simple filter design procedure using compensated operational amplifiers

Abstract

The effect of using a compensated operational amplifier in the design of second-order, minimum capacitor, active RC filters is [studied. A state-space description for the filter leads to a set of necessary conditions, in algebraic and topological forms, such that important properties of the ideal filter structure are achieved. These conditions are easily derived from the ideal structure. A simple design procedure enables the designer to get the moat out of the gain-bandwidth of the amplifier, obtaining an exact location for the pair of complex poles, while increasing considerably the frequency range where the structure is usable.