A Nanopower Folded-Cascode EEG Lowpass Filter

IF 4 2区工程技术 Q2 ENGINEERING, ELECTRICAL & ELECTRONIC

IEEE Transactions on Circuits and Systems II: Express Briefs Pub Date : 2025-02-25 DOI:10.1109/TCSII.2025.3545968

Surachoke Thanapitak;Khanittha Kaewdang;Xiao Liu;Prajuab Pawarangkoon

{"title":"A Nanopower Folded-Cascode EEG Lowpass Filter","authors":"Surachoke Thanapitak;Khanittha Kaewdang;Xiao Liu;Prajuab Pawarangkoon","doi":"10.1109/TCSII.2025.3545968","DOIUrl":null,"url":null,"abstract":"This brief presents a continuous-time lowpass biquadratic cell developed from a folded-cascode OTA operating in the subthreshold region. The proposed cell has been implemented by configuring the OTA in a unity-gain feedback manner and inserting two individual capacitors into the output and internal folding nodes. This allows the proposed biquadratic cell to benefit from the high loop gain that maintains good linearity at passband frequencies well below its cutoff. As an application of this biquadratic cell, a pseudo-differential lowpass filter for electroencephalogram detection is designed and implemented in a 0.18-<inline-formula> <tex-math>$\\mu $ </tex-math></inline-formula> m standard CMOS technology. The custom filter occupies a silicon area of <inline-formula> <tex-math>$230~\\mu $ </tex-math></inline-formula> m <inline-formula> <tex-math>$\\times 300~\\mu $ </tex-math></inline-formula> m and operates from a 0.8-V dc supply with 7 nA total current consumption. Multi-chip measurements exhibit the average cut-off frequency at 151.2 Hz, input-referred noise of <inline-formula> <tex-math>$35~\\mu $ </tex-math></inline-formula> Vrms, and linear range of 110 mVP. This brief achieves the best FoM to date among recent relevant nano-power filters.","PeriodicalId":13101,"journal":{"name":"IEEE Transactions on Circuits and Systems II: Express Briefs","volume":"72 5","pages":"643-647"},"PeriodicalIF":4.0000,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"IEEE Transactions on Circuits and Systems II: Express Briefs","FirstCategoryId":"5","ListUrlMain":"https://ieeexplore.ieee.org/document/10904172/","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, ELECTRICAL & ELECTRONIC","Score":null,"Total":0}

引用次数: 0

Abstract

This brief presents a continuous-time lowpass biquadratic cell developed from a folded-cascode OTA operating in the subthreshold region. The proposed cell has been implemented by configuring the OTA in a unity-gain feedback manner and inserting two individual capacitors into the output and internal folding nodes. This allows the proposed biquadratic cell to benefit from the high loop gain that maintains good linearity at passband frequencies well below its cutoff. As an application of this biquadratic cell, a pseudo-differential lowpass filter for electroencephalogram detection is designed and implemented in a 0.18-

$\mu $

m standard CMOS technology. The custom filter occupies a silicon area of

$230~\mu $

$\times 300~\mu $

m and operates from a 0.8-V dc supply with 7 nA total current consumption. Multi-chip measurements exhibit the average cut-off frequency at 151.2 Hz, input-referred noise of

$35~\mu $

Vrms, and linear range of 110 mVP. This brief achieves the best FoM to date among recent relevant nano-power filters.

查看原文本刊更多论文

一种纳米级折叠级联EEG低通滤波器

本文介绍了一种由折叠级联码OTA发展而来的在亚阈值区域工作的连续时间低通双二次单元。通过以单位增益反馈方式配置OTA，并在输出和内部折叠节点中插入两个单独的电容器，实现了所提出的单元。这使得所提出的双二次单元受益于高环路增益，在远低于其截止频率的通带频率下保持良好的线性度。作为该双二次单元的应用，设计并实现了一个用于脑电图检测的伪差分低通滤波器，采用0.18- $\mu $ m标准CMOS技术。定制滤波器的硅面积为$230~\mu $ m乘以$ 300~\mu $ m，工作在0.8 v直流电源下，总电流消耗为7na。多芯片测量显示，平均截止频率为151.2 Hz，输入参考噪声为$35~ $ μ $ Vrms，线性范围为110 mVP。该简报实现了迄今为止最新相关纳米功率滤波器中最好的FoM。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

IEEE Transactions on Circuits and Systems II: Express Briefs 工程技术-工程：电子与电气

CiteScore

7.90

自引率

20.50%

发文量

883

审稿时长

3.0 months

期刊介绍： TCAS II publishes brief papers in the field specified by the theory, analysis, design, and practical implementations of circuits, and the application of circuit techniques to systems and to signal processing. Included is the whole spectrum from basic scientific theory to industrial applications. The field of interest covered includes: Circuits: Analog, Digital and Mixed Signal Circuits and Systems Nonlinear Circuits and Systems, Integrated Sensors, MEMS and Systems on Chip, Nanoscale Circuits and Systems, Optoelectronic Circuits and Systems, Power Electronics and Systems Software for Analog-and-Logic Circuits and Systems Control aspects of Circuits and Systems.