可穿戴脑电监测系统的低功耗逐次逼近型模数转换器设计  

Design of Low Power SAR ADC for Wearable EEG Monitoring System

作　　者：潘梓忱 姚剑敏[1,2] 严群 PAN Zichen;YAO Jianmin;YAN Qun(College of Physics and Information Engineering,Fuzhou University,Fuzhou 350108,China;Jinjiang RichSence Electronic Technology Company Limited,Jinjiang 362200,China)

机构地区：[1]福州大学物理与信息工程学院,福建福州350108 [2]博感电子科技有限公司,福建晋江362200

出　　处：《仪表技术》2023年第6期5-8,42,共5页Instrumentation Technology

基　　金：中央引导地方科技发展专项(2021L3004)。

摘　　要：基于TSMC 180 nm芯片工艺,设计了一个用于可穿戴脑电监测的10位低功耗逐次逼近型模数转换器(SAR ADC)。为了有效降低DAC电容阵列的切换功耗,采用新型差分DAC电容阵列,并使用单调开关切换方式。比较器采用两级动态比较器,在提高效率的同时也降低功耗及噪声。针对脑电信号的特点,采用栅压自举开关实现高线性的采样。后仿真结果表明:在1.8 V供电电压、40 kS/s采样率下,这款SAR ADC的功耗仅为2.4μW,其有效位数(ENOB)为9.68 bit,无杂散动态范围(SFDR)为70.6 dB,优值为73.1 fJ/(conv-step),设计的SAR ADC适用于可穿戴脑电监测设备。Based on TSMC 180 nm process,a 10-bit low power SAR ADC for wearable EEG monitoring was designed.In order to cut down the switching power consumption of the DAC capacitor array effectively,a new differential DAC capacitor array is adopted,and a monotonic switching method is used.The comparator uses a two-stage dynamic comparator,which reduces power consumption and noise while improving efficiency.Aiming at the characteristics of EEG signals,a grid voltage bootstrap switch is used to achieve high linear sampling.The post-simulation results show that:at 1.8 V supply voltage and 40 kS/s sampling rate,the power consumption of this SAR ADC is only 2.4μW,its effective number of bits(ENOB)is 9.68 bits,and the spurious-free dynamic range(SFDR)is 70.6 dB,and the figure of merit is 73.1 fJ/(conv-step).The designed SAR ADC is suitable for wearable EEG monitoring equipment.

关 键 词：脑电信号 低功耗 逐次逼近寄存器 模数转换器 单调开关切换 

分 类 号：TN792[电子电信—电路与系统]