Design of hybrid integrated-filter building blocks

An economical approach to integrated active RC filter design is described. Complex filter networks are broken down into a small family of cascadable second-order filter building blocks consisting of tantalum thin-film RC networks and semiconductor, integrated, operational amplifiers. The same building blocks are used for any desired filter configuration such as low-pass, high-pass, or bandpass filters, all-pass networks, notch filters, etc. Therefore, they possess the uniformity necessary for high-production quantities and batch processing, and consequently, benefit from the economical advantages that go with these methods.