This paper discusses certain important issues involved in the design of a nerve signal preamplifier for implantable neuroprostheses. Since the electroneurograin signal measured from cuff electrodes is typically on the order of 1 uV, a very low-noise interface is essential. We present the argument for the use of BiCMOS technology in, this application and then, describe the design and evaluation of a complete preamplifier fabricated in a 0.8-mum double-metal double-poly process. The preamplifier has, a nominal voltage gain of 100, a bandwidth of 15 kHz; and a measured equivalent input-referred noise voltage spectral density of 3.3 nV/rootHz at 1 kHz. The total input-referred rms noise voltage in a bandwidth 1 Hz-10 kHz is 290 nV, the power consumption is 1.3 mW from +/-2.5-V power supplies, and the active area is 0.3 mm(2).
Rieger, R., Taylor, J., Demosthenous, A., Donaldson, N., & Langlois, P. J. (2003). Design of a low-noise preamplifier for nerve cuff electrode recording. IEEE Journal of Solid-State Circuits, 38(8), 1373-1379. https://doi.org/10.1109/jssc.2003.814437