Demonstration of a fully differential VGA chip with small THD for ECG acquisition system  

作　　者：肖功利 覃玉良 徐卫林 韦保林 段吉海 韦雪明 

机构地区：[1]School of Information and Communication,Guilin University of Electronic Technology [2]Guangxi Experiment Center of Information Science

出　　处：《Journal of Semiconductors》2015年第10期117-122,共6页半导体学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Nos.61264001,61465004,61161003,61166004);the Guangxi Natural Science Foundation(Nos.2013GXNSFAA019333,2013GXNSFAA019338);the Science and Technology Research Key Project of Guangxi Department of Education(No.2013ZD026);the Innovation Project of GUET Graduate Education(No.GDYCSZ201457)

摘　　要：We present both a theoretical and experimental demonstration of a fully differential variable gain am- plifier （VGA） with small total harmonic distortion （THD） for an electrocardiogram （ECG） acquisition system. Capacitive feedback technology is adopted to reduce the nonlinearity of VGA. The fully differential VGA has been fabricated in SMIC 0.18-μm CMOS process, and it only occupies 0.11 mm2. The measurements are in good agreement with simulation results. Experimental results show that the gain of VGA changes from 6.17 to 43.75 dB with a gain step of 3 dB. The high-pass comer frequency and low-pass comer frequency are around 0.22 Hz and 7.9 kHz, respectively. For each gain configuration, a maximal THD of 0.13% is obtained. The fully differential VGA has a low THD and its key performance parameters are well satisfied with the demands of ECG acquisition system application in the UWB wireless body area network.We present both a theoretical and experimental demonstration of a fully differential variable gain am- plifier （VGA） with small total harmonic distortion （THD） for an electrocardiogram （ECG） acquisition system. Capacitive feedback technology is adopted to reduce the nonlinearity of VGA. The fully differential VGA has been fabricated in SMIC 0.18-μm CMOS process, and it only occupies 0.11 mm2. The measurements are in good agreement with simulation results. Experimental results show that the gain of VGA changes from 6.17 to 43.75 dB with a gain step of 3 dB. The high-pass comer frequency and low-pass comer frequency are around 0.22 Hz and 7.9 kHz, respectively. For each gain configuration, a maximal THD of 0.13% is obtained. The fully differential VGA has a low THD and its key performance parameters are well satisfied with the demands of ECG acquisition system application in the UWB wireless body area network.

关 键 词：fully differential VGA total harmonic distortion ECG acquisition system capacitive feedback 

分 类 号：R540.4[医药卫生—心血管疾病] TP274.2[医药卫生—内科学]