应用于可穿戴脉搏血氧检测的G_m-C低通滤波器  

G_m-Clow pass filter for wearable pulse oximetry monitoring

作　　者：郑朝霞[1] 曾小刚 邹连英[2] 蒋潘婷 

机构地区：[1]华中科技大学光学与电子信息学院,湖北武汉430074 [2]武汉工程大学电气信息学院,湖北武汉430074

出　　处：《华中科技大学学报（自然科学版）》2017年第11期1-5,共5页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(61006028);科技部科技型中小企业技术创新基金资助项目(14C26214422753);湖北省重大科技资助项目(2015ACA063);中央高校基本科研业务费资助项目(2014TS041)

摘　　要：为了解决可穿戴脉搏血氧检测芯片滤波器面积大、功耗高的问题,改进设计了一个三阶巴特沃斯G_mC低通滤波器.线性跨导器采用源极负反馈结构来增大线性范围,并且输入管工作在亚阈值区降低了功耗,然后通过密勒效应放大电容来减小面积;同时,该滤波器通过开关电容调谐电路调制滤波器的截止频率,降低工艺偏差.仿真结果表明:在SMIC 0.18μm CMOS工艺,1.8V电源电压供电下,该低通滤波器的截止频率为7.9Hz,面积为0.14mm^2,功耗为6.7μW,相比其他的设计方案,在功耗和面积上都有大幅优化.To improve the large area and high power consumption of the on chip low pass filter for pulse oximetry,a third-order Butterworth G_m-Clow pass filter was proposed.Source negative feedback structure was used to improve the input voltage range and the input transistors worked in subthreshold region could reduce power consumption.Then,the capacitance was amplified by Miller effect to decrease the area.In addition,an automatic tuned circuit based on switched-capacitor circuit was used to precisely control the cut-off frequency of this filter,which could reduce the process deviation.Simulation results show that the filter achieves a low frequency of 7.9 Hz,a small area of 0.14 mm2 and a low power consumption of 6.7μW in SMIC 0.18μm CMOS technology under 1.8 Vsupply voltage,which are improved greatly compared with other references.

关 键 词：血氧检测 低通滤波器 可穿戴 自动调谐电路 线性跨导器 

分 类 号：TN47[电子电信—微电子学与固体电子学]