A high-gain, low-noise amplifier for EEG

Abstract

This paper describes an amplifier for an electroencephalograph with gain of 1×10 4 to 1×10 6 and made entirely of commercially available IC components. The two-stage amplifier has a preamplifier stage with fixed gain of 1000, and a second stage with variable gain from 1 to 100. The final stage, an anti-aliasing filter, adds a gain of 10 to the signal. The circuit has high common mode rejection, low input bias current, very low noise characteristics, low offset voltages, and offset nulling capability built into the circuit. © 1988 Psychonomic Society, Inc.