SBOSAA5B April 2022 – September 2022 OPA2675
Wideband current-feedback op amps make ideal elements for implementing high-speed active filters where the amplifier is used as a fixed gain block inside a passive RC circuit network. The relatively constant bandwidth versus gain provides low interaction between the actual filter poles and the required gain for the amplifier. shows an example single-supply buffered filter application. In this case, one of the OPA2675 channels is used to set up the dc operating point and provide impedance isolation from the signal source into the second-stage filter. That stage is set up to implement a 20 MHz, maximally flat Butterworth frequency response and provide an ac gain of +4 V/V.