Low-power low noise amplifier with tunable band for neural signal recording

We present the design and simulation of a low noise and a low power fully integrated band-pass amplifier for neural recording applications for work in a very low frequency range. This biosignal amplifier is capable to process neuronal signals in the millihertz to kilohertz frequency range while rejecting input DC offset voltage generated at the electrode-tissue interface. The readout channel is designed in 0.35 μm CMOS process and its total area is 0.24 mm
²
. The amplifier has a gain 40 dB, a low cut-off frequency tunable from 14 mHz to 1.4 Hz and a high cut-off frequency tunable from 2.4 kHz to 9.5 kHz. The input-referred noise is below 6 μV
rms
(integrated from 1 mHz to 100 kHz) and the single readout channel consumes 200 μW power from ±1.5 V supply, what makes it a good candidate for multichannel ASIC.