DocumentCode :
3046736
Title :
A capacitively-coupled biomedical instrumentation amplifier employing chopping and auto-zeroing
Author :
Peng Sun ; Menglian Zhao ; Xiaobo Wu ; Qing Liu
Author_Institution :
Inst. of VLSI Design, Zhejiang Univ., Hangzhou, China
fYear :
2012
fDate :
28-30 Nov. 2012
Firstpage :
61
Lastpage :
64
Abstract :
This paper presents a low power high precision instrumentation amplifier (IA) for biomedical electronics such as EEG, ECG and neural recording. By using capacitively-coupled topology, wide input common-mode range and low power consumption is achieved. Chopping and auto-zeroing techniques are employed simultaneously to alleviate their own side-effects. A DC cancellation loop is used to suppress electrode offset. In addition, adverse effect of parasitic capacitances of input transistors is analyzed and alleviated. Improved switched-capacitor (SC) CMFB circuits are proposed to mitigate capacitance load effect. This IA is implemented in SMIC 0.18μm CMOS process. -3dB bandwidth of the IA can be set as 1 kHz or 10 kHz to fit different applications like EEG or neural recording. Simulation results show that it achieves equivalent input noise power spectrum density (PSD) of 42nV/√Hz, a noise efficiency factor (NEF) of 3.1 and CMRR of 128dB. It consumes 3.7μA from a 1V supply.
Keywords :
CMOS integrated circuits; biomedical electrodes; biomedical electronics; electrocardiography; electroencephalography; instrumentation amplifiers; neurophysiology; power consumption; switched capacitor networks; transistors; DC cancellation loop; ECG; EEG; SMIC CMOS process; autozeroing techniques; biomedical electronics; capacitance load effect; capacitively-coupled biomedical instrumentation amplifier; capacitively-coupled topology; chopping techniques; current 3.7 muA; electrode offset; equivalent input noise power spectrum density; frequency 1 kHz; frequency 10 kHz; input transistors; low-power consumption; low-power high precision instrumentation amplifier; neural recording; noise efficiency factor; parasitic capacitances; size 0.18 mum; switched-capacitor CMFB circuits; voltage 1 V; wide input common-mode range; Bandwidth; Capacitors; Choppers (circuits); Electroencephalography; Impedance; Instruments; Noise;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Biomedical Circuits and Systems Conference (BioCAS), 2012 IEEE
Conference_Location :
Hsinchu
Print_ISBN :
978-1-4673-2291-1
Electronic_ISBN :
978-1-4673-2292-8
Type :
conf
DOI :
10.1109/BioCAS.2012.6418510
Filename :
6418510
Link To Document :
بازگشت