集成电路与嵌入式系统2025，Vol.25Issue(2)：1-10,10.DOI:10.20193/j.ices2097-4191.2024.0076
应用于生物阻抗测量的24位三阶四比特单环前馈增量式∑-ΔADC
A 24-bit incremental sigma-delta ADC with a 3rd-order,4-bit single-loop feedforward structure for bioimpedance measurement
摘要
Abstract
Bioimpedance measurement technology serves as a vital tool for medical diagnosis and health monitoring in various emerging medical instruments,in which the high-precision readout circuit is a crucial module for achieving accurate diagnoses.Traditional readout circuits in bioimpedance measurement systems often utilize SAR ADCs,which can hardly achieve an accuracy exceeding 12 bits to meet the increasingly high-precision demands for bioimpedance readout without calibration.To deal with this issue,this paper presents a 24-bit incremental ∑-ΔADC designed for bioimpedance measurement which adopts a 3rd-order,4-bit,single-loop feedforward structure to reduce quantization noise while accelerate the conversion speed.The design incorporates data weighted averaging(DWA)technique to mitigate the nonlinearity caused by multibit feedback DAC's mismatch,significantly enhancing the ADC's accuracy.In addition,sys-tem-level chopping is employed to eliminate systematic offset in the ADC frontend.A configurable digital filter is designed to achieve flexible tradeoff between measurement time and by configuring different oversampling ratios(OSR).The ADC is fabricated using a 180 nm process,with measurement results under an OSR of 128 showing that the ADC achieves an ENOB of 17.80,a SNR of 108.89 dB,a THD of-113.29 dB,an equivalent input RMS noise of 2.95 μVRMS.The power consumption is 930 μW for the whole ADC chip.关键词
生物阻抗测量/高阶增量式∑-ΔADC/多比特量化/DWA算法/系统级斩波Key words
bioimpedance measurement/high-order incremental ∑-ΔADC/multi-bit quantization/dynamic weight averaging algorithm/system-level chopping分类
信息技术与安全科学引用本文复制引用
孙傲然,陈长欢,陈阳,孙权,张杰,王晓飞,张鸿..应用于生物阻抗测量的24位三阶四比特单环前馈增量式∑-ΔADC[J].集成电路与嵌入式系统,2025,25(2):1-10,10.基金项目
江苏省科技计划揭榜挂帅项目(BE2023005-5) （BE2023005-5）
国家重点研发计划项目(2022YFC2404902). （2022YFC2404902）
