An 8-channel 2.1 μ W0.017 mm2 0.04% Gain Mismatch Bio-potential Recording AFE using Group-Chopping Technique

An 8-ch bio-potential recording AFE with less than 0.04% gain mismatch is presented. The proposed Group-Chopping Instrumentation Amplifier (GCIA) exploits group-chopping scheme with 8-phase non-overlapping clocks to achieve the lowest gain mismatch reported to date and improves between-channel CMRR among all channels, while mitigating dynamic offsets at once. The proposed GCIA is the first in literature to mitigate gain mismatch for more than 2 channels. Fabricated in 0.18 μm CMOS, it consumes 2.1μ W/Ch. under 0.5V supply and achieves NEF of 2.1, while occupying 0.017mm
²
/Ch.