基于生物应用的低截止频率5阶G_m-C低通滤波器  

A Fifth-Order G_m-C Low-Pass Filter with Very Low Cut-Off Frequency for Biological Application

作　　者：李怡[1] 段宝兴[1] 王勇[1] 杨银堂[1] 

机构地区：[1]西安电子科技大学微电子学院,西安710071

出　　处：《半导体技术》2017年第6期453-457,共5页Semiconductor Technology

摘　　要：设计了一款基于生物应用的截止频率为38.49 Hz的5阶跨导电容(G_m-C)低通滤波器。首先利用电流互抵技术设计实现了一款低G_m的运算跨导放大器(OTA),并基于此OTA,采用无源电感电容(LC)网络模拟法设计了一款5阶椭圆滤波器。最后基于华虹宏力0.35μm CD350 60 V/80 V工艺应用Spectre仿真工具对滤波器进行仿真。结果表明,所设计的低通滤波器可以实现非常陡峭的过渡带,并在50 Hz工频信号处衰减达-43.812 dB;阻带衰减为-33.18 dB;通带内平均噪声为352.0μV·Hz^(-1/2);总谐波失真为-56.24 d B;3.3 V电源电压下,5阶滤波器总功耗仅为11.73μW。所设计的滤波器可以有效采集频率极低的生物信号并且滤除干扰信号。芯片面积为1 200μm×728μm。A fifth-order Gm-C low-pass filter with a cut-off frequency of 38.49 Hz for biological ap- plication was desighed. Firstly, an operational transconductance amplifier （OTA） with a low transcon- duction was designed by using the current cancellation technology. Then, based on the OTA, a fifth-or- der elliptic filter was designed by the passive inductance capacitance （LC） network simulation method. Finally, the filter was simulated based on the 0.35 μm CD350 60 V/80 V process of Huahong grace with spectre platform. The results show that designed low-pass filter can achieve a very steep transition zone, an attenuation of -43. 812 dB in 50 Hz, and a stop band attenuation of -33.18 dB. The average noise in pass band is 352.0 μV · Hz -1/2, the total harmonic distortion is -56.24 dB, and the total power consumption of the fifth-order filter is only 11.73 μW under the power supply 3.3 V. The designed filter can effectively capture the very low frequency of biological signals and filter out the interference signal. The area of chip layout is 1 200 μm×728 μm.

关 键 词：跨导运算放大器(OTA) 电流互抵 Gm-C低通滤波器 低截止频率 生物应用 

分 类 号：TN722.75[电子电信—电路与系统]