CMOS Low Current Measurement System for Biomedical Applications

Author

Goldstein, B. ; Dongsoo Kim ; Jian Xu ; Vanderlick, T.K. ; Culurciello, E.

Author_Institution

Dept. of Electr. Eng., Yale Univ., New Haven, CT, USA

Volume

6

Issue

2

fYear

2012

fDate

4/1/2012 12:00:00 AM

Firstpage

111

Lastpage

119

Abstract

We present a micro-chip implementation of a low current measurement system for biomedical applications using capacitive feedback that exhibits 190 fA of RMS noise in a 1 kHz bandwidth. The sampling rate is selectable up to 100 kHz. When measuring the amplifier noise with a 10 G Ω resistor and a 47 pF capacitor at the input, typical of cell membrane capacitance in DNA and patch clamp experiments, the measured RMS noise was 2.44 pA on a 50 pA signal in a 10 kHz bandwidth. Two channels were implemented on 630 × 440 μm² using a 0.5- μm 3-metal 2-poly CMOS process. Each channel consumes 1.5 mW of power from a 3.3 V supply. We measured the characteristics of an artificial lipid bilayer similar to the ones used in DNA sequencing experiments via nanopores.

Keywords

CMOS integrated circuits; DNA; biomedical electronics; biomedical measurement; biomembranes; capacitance; cellular biophysics; electric current measurement; lipid bilayers; molecular biophysics; DNA sequencing; RMS noise; amplifier noise; artificial lipid bilayer; capacitive feedback; cell membrane capacitance; frequency 1 kHz; low current measurement; microchip; patch clamp; power 1.5 mW; resistance 10 Gohm; sampling rate; voltage 3.3 V; Biomedical measurements; Capacitance; Current measurement; Electrodes; Noise; Noise measurement; Voltage measurement; Amperometry; biomedical measurements; capacitive feedback; current measurement; integrator; low current measurement system; low noise circuit; noise analysis; potentiostat; voltage-clamp;

fLanguage

English

Journal_Title

Biomedical Circuits and Systems, IEEE Transactions on

Publisher

ieee

ISSN

1932-4545

Type

jour

DOI

10.1109/TBCAS.2011.2182512

Filename

6152173