An ultra-low-power neural recording amplifier and its use in adaptively-biased multi-amplifier arrays

The design of a micropower energy-efficient neural recording amplifier is presented. The amplifier appears to be the lowest power and most energy-efficient neural recording amplifier reported to date. I describe low-noise design techniques that help the neural amplifier achieve an input-referred noise that is near the theoretical limit of any amplifier using a differential pair as an input stage. The bandwidth of the amplifier can be adjusted for recording either neural spikes or local field potentials (LFP). When configured for recording neural spikes, the amplifier yielded a midband gain of 40.8 dB and -3 dB bandwidth from 45 Hz to 5.32 kHz; the amplifier's input-referred noise was measured to be 3.06 [mu]Vrms, while consuming 7.56 [mu]W of power from a 2.8 V supply corresponding to a Noise Efficiency Factor (NEF) of 2.67 with the theoretical limit being 2.02. When configured for recording LFPs, the amplifier achieved a midband gain of 40.9 dB and a -3 dB bandwidth from 392 mHz to 295 Hz; the input-referred noise was 1.66 [mu]Vrms, while consuming 2.08 AW from a 2.8 V supply corresponding to an NEF of 3.21. The amplifier was fabricated in AMI's 0.5 im CMOS process and occupies 0.16 mm2 of chip area. The designs of two previous amplifiers that have been attempted are also presented. Even though they do not achieve optimal performances, the design insights obtained have led to a successful implementation of the energy-efficient neural amplifier discussed above.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Wattanapanitch, Woradorn

Advisor dc:contributor.advisor

• Rahul Sarpeshkar.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/40541

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/40541