An improved, very long time-constant CMOS integrator for use in implantable neuroprosthetic devices

This paper describes a CMOS integrator for use with an adaptive neural amplifier. The device can also be used standalone. It utilizes transconductance cancellation to achieve a large time-constant, which is tunable between 1-17 s. The design presented here features reduced complexity compared to previous published work for that application. Measured results demonstrate integration with no output drift, tunable time-constant and low total harmonic distortion. The device can also be operated as a low-pass filter.