Vital IC

ExG Biosignal Acquisition

Low Power, Low Noise, High CMRR, High Input Impedance and Wide Input Range

Challenges

  • Low power consumption : <10 μW

  • Low noise : <1 μVrms

  • Large input swing : >200 mVPP

  • Wide dynamic range : >90 dB

  • High CMRR : >70 dB

  • High input impedance : >100 MΩ

Obstacles in ExG Biosignal Acquisition

  • Electrode DC offset

  • Electrode impedance

  • Common-mode artifacts

  • Circuit noise

Low Noise vs High Impedance

  • With chopper stabilization

    • Low 1/f noise and high CMRR(Common Mode Rejection Ratio)

    • Additional amplifier required for input impedance boosting due to low Zin

  • Without chopper stabilization

    • Vulnerable to 1/f noise and common-mode interference

    • High Zin

** Impedance boosting technique should be applied for low noise and high impedance implementation

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