A low-cost parallel implementation for active filters

A circuit technique is proposed, based upon a parallel-structured system, that attempts to reduce the overall component cost required for a general m-pole transfer function. The circuit uses just m nominally equal-valued capacitors, irrespective of the number of zeros. Whilst the zero sensitivity of the parallel structure is expected to be rather poorer than that for the cascade circuit, it has been found acceptable for the example described. The pole sensitivity is the same as that for the more conventional cascade structure.