Title :
A 1μW 85nV/√Hz pseudo open-loop preamplifier with programmable band-pass filter for neural interface system
Author :
Chang, Sun-Il ; Yoon, Euisik
Author_Institution :
Electr. Eng. & Comput. Sci. Dept., Univ. of Michigan, Ann Arbor, MI, USA
Abstract :
We report an energy efficient pseudo open-loop amplifier with programmable band-pass filter developed for neural interface systems. The proposed amplifier consumes 400 nA at 2.5 V power supply. The measured thermal noise level is 85 nV/radic(Hz) and input-referred noise is 1.69 muVrms from 0.3 Hz to 1 kHz. The amplifier has a noise efficiency factor of 2.43, the lowest in the differential topologies reported up to date to our knowledge. By programming the switched-capacitor frequency and bias current, we could control the bandwidth of the preamplifier from 138 mHz to 2.2 kHz to meet various application requirements. The entire preamplifier including band-pass filters has been realized in a small area of 0.043 mm2 using a 0.25 mum CMOS technology.
Keywords :
CMOS integrated circuits; band-pass filters; biomedical electrodes; biomedical electronics; brain-computer interfaces; medical signal processing; neurophysiology; preamplifiers; programmable filters; switched capacitor filters; CMOS technology; bias current; current 400 nA; differential topology; frequency 0.3 Hz to 1 kHz; frequency 138 mHz to 2.2 kHz; input-referred noise; neural interface system; noise efficiency factor; power 1 muW; programmable band-pass filter; pseudo open-loop preamplifier; switched-capacitor frequency; thermal noise level; voltage 2.5 V; Electrodes; Neural Networks (Computer);
Conference_Titel :
Engineering in Medicine and Biology Society, 2009. EMBC 2009. Annual International Conference of the IEEE
Conference_Location :
Minneapolis, MN
Print_ISBN :
978-1-4244-3296-7
Electronic_ISBN :
1557-170X
DOI :
10.1109/IEMBS.2009.5334233
