Active RC filter having gain-setting attenuator

摘要

Disclosed herein are embodiments of an active RC filter that has a gain-setting attenuator. An embodiment takes the form of a filter circuit having a filter-circuit input node; a filter-circuit output node; an operational amplifier (op-amp) having first and second inputs and also having an output coupled to the filter-circuit output node; and a passive feedback path extending between the filter-circuit output node and the first op-amp input, the passive feedback path having a gain-setting attenuator segment in series with a signal-filtering segment.

主权项

1. A filter circuit comprising:
a filter-circuit input node; a filter-circuit output node; an operational amplifier (op-amp) comprising first and second op-amp inputs, the op-amp further comprising an op-amp output coupled to the filter-circuit output node; and a passive feedback path extending between the filter-circuit output node and the first op-amp input, the passive feedback path comprising a variable gain-setting attenuator for varying filter circuit gain separate from and in series with a signal-filtering RC network for varying filter circuit bandwidth and quality factor, such that filter circuit gain can be changed independently without impacting filter circuit bandwidth or quality factor.