Low-noise low-power CMOS preamplifier for multisite extracellular neuronal recordings

This paper reports the design and the experimental results of a fully integrated, low-noise, low-power standard CMOS preamplifier circuit used to record the extracellular electrophysiological activity of in vitro biological neuronal cultures. Our goal is to use the preamplifier in a fully integrated multi-channel,, bi-directional neuro-electronic interface. Among others, two main requirements must be addressed when designing such kind of integrated recording systems: noise performance and very low frequency disturbance rejection. These two requirements need to be satisfied together with a small silicon area design, to be able to integrate a large number of recording channels (i.e. up to thousands) onto a single die. A prototype preamplifier circuit has been designed and implemented; in this paper we report the experimental results. While satisfying the above requirements, our circuit offers state-of-the-art smallest area occupation (0.13 mm(2)) and consumes 4.5 mu W. Sub-threshold-biased lateral pnp transistors, used to implement very high resistance value integrated resistors, have been characterized to determine the resistance spread. The fabricated prototype, coupled with a commercial Micro-Electrode Array (MEA), has been successfully employed to record the extracellular electrophysiological spontaneous activity, both of muscular cardiac cells (cardiomyocytes) and of spinal cord neurons from murines. (C) 2009 Elsevier Ltd. All rights reserved.