Low-Sensitivity Active-RC Allpole Filters Using Optimized Biquads

In this paper we present an optimal design procedure for secondand third-order active resistance-capacitance (RC) single-amplifier building blocks that are used to build a high-order tolerance-insensitive allpole filter. The design procedure of low-sensitivity, low-pass secondand third-order active-RC allpole filters, with positive feedback, has already been published. The design was extended to the high-pass and band-pass filters, as well as, to the filters using negative feedback. In this paper we summarize all these previously presented designs in the form of a tabulated step-by-step design framework (cookbook). The low passive sensitivity of the resulting circuits, as well as low active sensitivity features are demonstrated on the high-order Chebyshev filter examples. The resulting low passive sensitivity is investigated using the Schoeffler sensitivity measure, whereas the low active sensitivity is investigated with Matlab using finite and frequency dependent opamp gain.