A CMOS IC for portable EEG acquisition systems

We present a monolithic low-power, low-noise analog front-end electroencephalogram acquisition system. It draws only 500 /spl mu/A from a standard 9-V battery, making it suitable for use in portable systems. Although fabricated in a standard CMOS technology, by using current feedback techniques it achieves a common mode rejection ratio of 100 dB while the total input noise referred to input is kept below 1.5 /spl mu/V (rms).