Although active filters are vital in modern electronics, theirdesign and verification can be tedious and time consuming.To aid in the design of active filters, Burr-Brown provides aseries of FilterPro™ computer-aided design programs. Usingthe FILTER42 program and the UAF42 it is easy todesign and implement all kinds of active filters. The UAF42is a monolithic IC which contains the op amps, matchedresistors, and precision capacitors needed for a state-variablefilter pole-pair. A fourth, uncommitted precision op amp isalso included on the die.