A 1.2-V 140-nW 10-bit Sigma–Delta Modulator for Electroencephalogram Applications

Author

Lopez-Morillo, E. ; Carvajal, R.G. ; Munoz, F. ; El Gmili, H. ; Lopez-Martin, A. ; Ramirez-Angulo, Jaime ; Rodriguez-Villegas, Esther

Author_Institution

Dept. de Ing. Electron., Univ. de Sevilla, Sevilla

Volume

2

Issue

3

fYear

2008

Firstpage

223

Lastpage

230

Abstract

This paper presents a second-order Sigma-Delta modulator for electroencephalogram applications with 10 bits of resolution, 1.2 V of supply voltage, and only 140 nW of power consumption over a bandwidth of 25 Hz. Low-voltage operation has been achieved using quasi-floating-gate-based circuits. The use of a new class-AB operational amplifier in weak inversion allows very low power consumption. Experimental results show an energy efficiency of 1.6 pJ per quantization level, making it the most energy-efficient converter reported to date in the very low signal bandwidth range.

Keywords

biomedical electronics; biomedical equipment; electroencephalography; medical signal processing; operational amplifiers; sigma-delta modulation; class AB operational amplifier; electroencephalogram applications; energy efficient converter; low voltage operation; power 140 nW; quasi-floating gate based circuits; second order Sigma-Delta modulator; voltage 1.2 V; Bandwidth; Biomedical measurements; Circuits; Electroencephalography; Energy consumption; Energy efficiency; Instruments; Low voltage; Operational amplifiers; Signal resolution; Analog–digital conversion; biomedical measurements; class-AB amplifiers; low power; low voltage; sigma–delta modulation;

fLanguage

English

Journal_Title

Biomedical Circuits and Systems, IEEE Transactions on

Publisher

ieee

ISSN

1932-4545

Type

jour

DOI

10.1109/TBCAS.2008.2001868

Filename

4660378