一种采用斩波稳定技术的Σ-Δ调制器  

A Chopper-stabilized sigma-delta modulator

作　　者：刘睿 田海燕 廖春连[1] 王旭东[1] LIU Rui;TIAN Hai-yan;LIAO Chun-lian;WANG Xu-dong(The 54th Research Institute of China Electronics Technology Group Corporation)

机构地区：[1]中国电子科技集团公司第五十四研究所

出　　处：《中国集成电路》2023年第12期57-65,共9页China lntegrated Circuit

摘　　要：为了抑制Σ-Δ调制器的直流失调及其温度漂移,并使调制器对版图失配具有更高的鲁棒性,本文设计了一种多处采用斩波调制的Σ-Δ调制器。通过对调制器第一级积分器采样路径、反馈路径和放大器进行斩波调制,电路有效抑制了版图失配和低频闪烁噪声对Σ-Δ调制器的不利影响,减小了Σ-Δ调制器的直流失调电压,提升了Σ-Δ调制器的信噪比。本文基于0.18μm CMOS工艺进行设计,供电电压为5V,在信号带宽为72KHz内,调制器信噪比达到113dB,即18.4位有效位数,直流失调降低至4.2μV,可以用于测量微小的传感器信号。In order to suppress the DC offset error and its temperature drift of theΣ-Δmodulator,and improve its robustness to layout mismatch,this paper describes a novel chopper-stabilized configuration.By inserting choppers at the sampling path,the DAC feedback path and the both ends of the amplifier,the effects of layout mismatches and flicker noise are mitigated,which reduces the offset error and improves the signal-to-noise ratio.The circuits are based on 0.18μm CMOS process.With 5V power voltage and 72KHz signal band,the signal-to-noise ratio of theΣ-Δmodulator reaches 113dB,namely 18.4 bits ENOB,and the offset error reduces to 4.2μV,which meet the needs of weak signal measurements.

关 键 词：Σ-Δ调制器 斩波稳定 失调误差 

分 类 号：TN761[电子电信—电路与系统]