New CFOA-based low frequency filters for biomedical and seismic applications

Abstract

This paper presents new low frequency filters. The proposed filters are built around a floating active inductor (FAI), a capacitance multiplier and/or a resistance multiplier. The proposed FAI, capacitance (resistance) multipliers uses two current feedback operational amplifiers (CFOAs) and five passive components and can realize relatively large values of inductances, capacitances and resistances that cannot be fabricated on chips. Experimental and simulation results that confirm the functionality of the proposed circuits are obtained using the commercially available CFOA AD844. The proposed filters would be useful for very low frequency applications such as biomedical devices used in the electrocardiogram (ECG), the electroencephalograph (EEG) measurements and the pacemaker detector as well as in seismic measurements.