A fully reconfigurable low-noise biopotential sensing amplifier

In this paper, we present a fully reconfigurable biopotential sensing amplifier, which employs floating-gate transistors for the programming of the low-frequency cutoff corner and for and for common-mode feedback implementation without consuming any extra power. With a supply voltage of 2.5V, the measured midband gain is 40.7dB and the measured input-referred noise is 2.8 μV_rms. The chip was tested under several configurations with the amplifier bandwidth being programmed to 100Hz, 1kHz, and 10 kHz. The measured noise efficiency factors in these bandwidth settings are 1.96, 2.01 and 2.25. The measured common-mode rejection and the supply rejection are above 70 dB. The measured dynamic range is 60 dB with total harmonic distortion less than 0.1%.