A biopotential amplifier with improved common mode gain

Author

Abdullah, Rusli ; Sanchez-Sinencio, Edgar

Author_Institution

Dept. of Electr. Eng., Texas A&M Univ., College Station, TX, USA

fYear

2013

fDate

Feb. 27 2013-March 1 2013

Firstpage

1

Lastpage

4

Abstract

In this paper, a technique is proposed for improving the Common Mode Rejection Ratio (CMRR) of opamp based Instrumentation Amplifiers in resistor-capacitor (RC) feedback configurations by dynamically matching input and feedback capacitor pairs. A fully differential biopotential amplifier is designed with the proposed dynamic element-matching scheme and its performance is compared with the case where dynamic element matching is switched off. Experimental results show that the proposed dynamic element matching technique improves CMRR by over 40 dB over the conventional case. The proposed technique also reduces average power consumption. The biopotential amplifier draws an average of 20uA of quiescent current from a 1.5V dual power supply source. The input referred noise is less than 3uV/sqrt (Hz).

Keywords

biomedical electronics; capacitors; instrumentation amplifiers; operational amplifiers; CMRR; RC feedback configurations; common mode rejection ratio; current 20 muA; dynamic element-matching scheme; feedback capacitor pairs; fully-differential biopotential amplifier; improved common mode gain; opamp-based instrumentation amplifiers; power consumption reduction; resistor-capacitor feedback configurations; voltage 1.5 V; Capacitors; Clocks; Gain; Instruments; Noise; Resistors; Topology;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems (LASCAS), 2013 IEEE Fourth Latin American Symposium on

Conference_Location

Cusco

Print_ISBN

978-1-4673-4897-3

Type

conf

DOI

10.1109/LASCAS.2013.6519050

Filename

6519050