Abstract:
This paper presents a 16-channel analog front-end (AFE) for wearable dry EEG recording. A novel AFE architecture that combines time division multiplexing (TDM) and choppi...Show MoreMetadata
Abstract:
This paper presents a 16-channel analog front-end (AFE) for wearable dry EEG recording. A novel AFE architecture that combines time division multiplexing (TDM) and chopping stabilization (CS) to improve the system common mode rejection ratio (CMRR) and the input-referred noise is proposed. With TDM, the reference electrode is connected to single channel input during its time slot to avoid the CMRR degradation caused by input impedance imbalance. Furthermore, the 2nd stage programmable gain amplifier (PGA) is shared among multiple channels, leading to significant reduction in both power consumption and chip area. In addition, input impedance boosting loop and DC servo-loop are included to boost the input impedance and cancel the input DC offset. Implemented in a 0.18-pm CMOS process, the proposed AFE shows 0.63 pVrms input-referred noise integrated from 0.5 Hz to 100 Hz and 560 MΩ input impedance at 50 Hz. The measured AFE intrinsic CMRR is 89 dB and the system CMRR is 82 dB, which is a 40 dB improvement compared to the conventional architecture. The AFE chip consumes merely 1.5 pW per channel under the 1 V supply voltage.
Published in: 2017 IEEE Asian Solid-State Circuits Conference (A-SSCC)
Date of Conference: 06-08 November 2017
Date Added to IEEE Xplore: 28 December 2017
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