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Article Abstract
This article reports on a compact and low-power CMOS readout circuit for bioelectrical signals based on a second-order delta-sigma modulator. The converter uses a voltage-controlled, oscillator-based quantizer, achieving second-order noise shaping with a single opamp-less integrator and minimal analog circuitry. A prototype has been implemented using 0.18 μm CMOS technology and includes two different variants of the same modulator topology. The main modulator has been optimized for low-noise, neural-action-potential detection in the 300 Hz-6 kHz band, with an input-referred noise of 5.0 μV, and occupies an area of 0.0045 mm. An alternative configuration features a larger input stage to reduce low-frequency noise, achieving 8.7 μV in the 1 Hz-10 kHz band, and occupies an area of 0.006 mm. The modulator is powered at 1.8 V with an estimated power consumption of 3.5 μW.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8512173 | PMC |
| http://dx.doi.org/10.3390/s21196456 | DOI Listing |
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