基于分时复用SAR ADC的Zoom ADC  

A Zoom ADC Based on Time-Division Multiplexing SAR ADC

作　　者：牛瑞玲 杨吉城 汪家奇[1] 李兆涵 刘国文 申人升[1] NIU Ruiling;YANG Jicheng;WANG Jiaqi;LI Zhaohan;LIU Guowen;SHEN Rensheng(School of Integrated Circuits,Dalian University of Technology,Dalian Liaoning 116000,China)

机构地区：[1]大连理工大学集成电路学院,辽宁大连116620

出　　处：《微处理机》2024年第4期1-7,共7页Microprocessors

基　　金：国家重点研发计划项目“高能效感算一体芯片与系统”(2023YFB4503003);2022年工业与信息化部产业再造与高质量发展专项(TC220A04A-49);装备预先研究共用技术项目(50917020302-1)。

摘　　要：为了在增加有限硬件开销的基础上实现更高的信号噪声抑制比、提高面积利用效率,提出一种基于分时复用SAR ADC的动态zoom ADC。同时提出一种提取粗量化模拟残差并前馈的无源实现方案,不需要有源求和运放的设计,避免了普通无源求和信号的衰减,减小了粗量化部分量化噪声泄露引起的“毛刺”。整体电路分为粗量化和细量化两部分进行设计,粗量化由3位异步SAR ADC实现,细量化由二阶3位量化的sigma-delta调制器实现。基于0.18μm CMOS工艺、3.3V供电电压,在1MHz采样频率下、1kHz带宽内,消耗76μA电流,得到信噪失真比和FOM的具体值,验证了设计的可行性。To achieve higher signal-to-noise ratio and area efficiency with limited hardware overhead,a dynamic zoom ADC based on time-division multiplexed SAR ADC is proposed.Meanwhile,a passive implementation scheme for extracting coarse quantized analog residues and feedforward is proposed,which does not require the design of an active summing operational amplifier,avoids the attenuation of common passive summing signals,and reduces the"fuzz"caused by coarse quantization noise leakage.The overall circuit is designed in two parts:coarse quantization and fine quantization.Coarse quantization is realized by a 3bit asynchronous SAR ADC,and fine quantization is realized by a second-order 3 bit sigma-delta modulator.Based on 0.18μm CMOS technology,3.3V supply voltage,1MHz sampling frequency,and 1kHz bandwidth,the current consumption is 76μA,and the specific values of signal-to-noise distortion ratio and FOM are obtained,verifying the feasibility of the design.

关 键 词：缩放型模数转换器 SIGMA-DELTA调制器 逐次逼近模数转换器 分时复用 

分 类 号：TN432[电子电信—微电子学与固体电子学]