Open AccessTuning approach for first‐order filters and new current‐mode circuit example
Author(s) -
Maheshwari Sudhanshu
Publication year - 2018
Publication title -
iet circuits, devices and systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.251
H-Index - 49
ISSN - 1751-8598
DOI - 10.1049/iet-cds.2017.0431
Subject(s) - filter (signal processing) , active filter , all pass filter , low pass filter , computer science , filter design , current conveyor , control theory (sociology) , electronic engineering , electronic filter , high pass filter , prototype filter , output impedance , electronic filter topology , capacitor , engineering , electrical impedance , voltage , electrical engineering , control (management) , artificial intelligence , computer vision
An approach of tuning first‐order filters is proposed in this study. The proposed approach is based on employing feedback in first‐order filter circuits, wherein a scaled output is combined with the input signal, so as to facilitate easy tuning of filter parameters. Various options of tuning the filter parameters are explored by employing feedback from low‐pass, high‐pass or all‐pass outputs. The approach enables easy tuning of filter parameters by varying the gain of an external amplifier, without adjusting the passive elements comprising the filter core. A new current‐mode filter circuit is further proposed, which employs a recently introduced active element, namely an extra‐X current conveyor. The new approach is used in the designed first‐order filter circuit. The new proposed circuit benefits by employing only a grounded capacitor, exhibits low‐input and high‐output impedances. The approach of tuning filter parameters through external means, without disturbing filter core, and the new proposed circuit are verified through simulations with promising results. As further modification to the proposed approach, the possibility of realising pole–zero symmetry is presented, which makes the new proposed tuning method useful for both existing and future designs.