Multiple-loop feedback topologies for the design of low-sensitivity active filters(Invited Paper)

Improved sensitivity performance of active filters in multiloop feedback (coupled) topologies is well known. Of the numerous design procedures available in the literature, in this paper those methods are reviewed which are based on first- or second-order building blocks in a feedback configuration. A statistical sensitivity measure is given which results in a realistic performance measure for the filters and which can be used to compare circuits and to optimize their design to achieve minimum sensitivity. Design procedures are provided for each topology, which result in realizations having minimum sensitivity and maximum dynamic range. Also, design tables for several examples are given, and the performance of some filters is demonstrated experimentally.