Low Transconductance OTA Based Active Comb Filter for Biomedical Applications

Abstract

This paper presents a comb filter to suppress power line interference in biomedical signals. The filter is based on OTA-C topology and the rejection frequency of the filter is tunable by changing the transconductance of the OTA. This filter is designed in Tanner EDA tool in 45 nm technology and is powered by 1.1 V supply. This Designed filter achieves a stop band attenuation of 24 dB for 50 Hz, 150 Hz and 250 Hz frequencies. A comb filter using OTA-C topology is designed. The filter is designed using 45 nm CMOS technology in Tanner EDA tool and simulated using TSPICE simulator. The performance of the filter is as expected. This filter has more number of active components than but has less number of passive components. One more advantage of OTA-C based filter design is that by simply controlling the bias current of OTAs, electronic tuning of filter parameters such as center frequency and quality factor can be achieved. Future scope of this design can be to implement it using low power OTA cell in 14 nm FinFET technology. This way power consumption and chip area will be reduced.