An 11 $\mu$w, two-electrode transimpedance biosignal amplifier with active current feedback stabilization
| Autor: | Omer T. Inan, Gregory T. A. Kovacs |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Transimpedance amplifier
Engineering Input offset voltage Current-feedback operational amplifier business.industry Biomedical Engineering Electrical engineering Fully differential amplifier law.invention law Operational transconductance amplifier Electronic engineering Operational amplifier Instrumentation amplifier Electrical and Electronic Engineering business Direct-coupled amplifier |
| Zdroj: | IEEE Transactions on Biomedical Circuits and Systems. 4:93-100 |
| ISSN: | 1940-9990 1932-4545 |
| DOI: | 10.1109/tbcas.2009.2032096 |
| Popis: | A novel two-electrode biosignal amplifier circuit is demonstrated by using a composite transimpedance amplifier input stage with active current feedback. Micropower, low gain-bandwidth product operational amplifiers can be used, leading to the lowest reported overall power consumption in the literature for a design implemented with off-the-shelf commercial integrated circuits (11 μW). Active current feedback forces the common-mode input voltage to stay within the supply rails, reducing baseline drift and amplifier saturation problems that can be present in two-electrode systems. The bandwidth of the amplifier extends from 0.05-200 Hz and the midband voltage gain (assuming an electrode-to-skin resistance of 100 kΩ) is 48 dB. The measured output noise level is 1.2 mV pp, corresponding to a voltage signal-to-noise ratio approaching 50 dB for a typical electrocardiogram (ECG) level input of 1 mVpp. Recordings were taken from a subject by using the proposed two-electrode circuit and, simultaneously, a three-electrode standard ECG circuit. The residual of the normalized ensemble averages for both measurements was computed, and the power of this residual was 0.54% of the power of the standard ECG measurement output. While this paper primarily focuses on ECG applications, the circuit can also be used for amplifying other biosignals, such as the electroencephalogram. |
| Databáze: | OpenAIRE |
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