Micropower fully integrated CMOS readout interface for neural recording application

In this paper, we presented a micropower, small-size fully integrated CMOS readout interface for neural recording system. A crucial and important module of this system is the amplifier circuit with low-power low-noise. We describe a micropower low-noise readout circuit using an active feedback fully differential structure to reject the 1/f noise and large DC-offsets, the substrate-bias technology to further decrease the noise and power of the neural recording amplifier. Therefore, the neural amplifier with micropower low-noise and high input impedance is presented. The readout interface core, fully differential amplifier is implemented in 0.35-μm CMOS process, passes neural signals from 10 Hz to 9 kHz with an input-referred noise of 4.3 μVrms. The power consumption of single amplifier is 5.6 μW while consuming 0.03 mm2 of die area. The low cutoff frequencies of the circuit can adjusted from 10 Hz to 400 Hz, and the high cutoff frequencies form 4 kHz to 9 kHz.