title: Design of ultra-low power biopotential amplifiers for biosignal acquisition applications.
abstract: Rapid development in miniature implantable electronics are expediting advances in neuroscience by allowing observation and control of neural activities. The first stage of an implantable biosignal recording system, a low-noise biopotential amplifier (BPA), is critical to the overall power and noise performance of the system. In order to integrate a large number of front-end amplifiers in multichannel implantable systems, the power consumption of each amplifier must be minimized. This paper introduces a closed-loop complementary-input amplifier, which has a bandwidth of 0.05 Hz to 10.5 kHz, an input-referred noise of 2.2 μ Vrms, and a power dissipation of 12 μW. As a point of comparison, a standard telescopic-cascode closed-loop amplifier with a 0.4 Hz to 8.5 kHz bandwidth, input-referred noise of 3.2 μ Vrms, and power dissipation of 12.5 μW is presented. Also for comparison, we show results from an open-loop complementary-input amplifier that exhibits an input-referred noise of 3.6 μ Vrms while consuming 800 nW of power. The two closed-loop amplifiers are fabricated in a 0.13 μ m CMOS process. The open-loop amplifier is fabricated in a 0.5 μm SOI-BiCMOS process. All three amplifiers operate with a 1 V supply.
authors.affiliation: Department of Electrical Engineering, University of Washington, Seattle,WA 98195 USA. fz2@u.washington.edu
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.forename: Jeremy
authors.initials: J
authors.lastname: Holleman
authors.forename: Brian P
authors.initials: BP
authors.lastname: Otis
mesh_terms: D000669:Amplifiers, Electronic; D001698:Biomedical Engineering; D001927:Brain Diseases / Q000628:therapy; D003201:Computers; D011211:Electric Power Supplies; D004581:Electronics; D004867:Equipment Design; D006801:Humans; D008904:Miniaturization; D009488:Neurosciences / Q000295:instrumentation*; D019736:Prostheses and Implants; D012815:Signal Processing, Computer-Assisted; D059015:Wireless Technology