一种双采样38-μ W92-dB8-kHz带宽ΣΔ调制器  

A Double-Sampling 38-μW 92-dB Sigma-Delta Modulator with 8-kHz Signal Bandwidth

作　　者：齐达[1] 李渊文[1] 叶凡[1] 许俊[1] 任俊彦[1] 李宁[1] 

机构地区：[1]复旦大学专用集成电路与系统国家重点实验室 微纳电子科技创新平台,上海201203

出　　处：《复旦学报（自然科学版）》2009年第4期517-522,526,共7页Journal of Fudan University：Natural Science

基　　金：国家“八六三”高技术研究发展计划资助项目(2008AA010702);国家重点实验室自主重点资助项目(ZD20080102)

摘　　要：提出了一种应用于助听器的单环3阶开关电容ΣΔ调制器,采用双采样技术通过提高过采样率来改善调制器的性能,详细分析了双采样中电容失配的影响.为进一步降低功耗,OTA采用了class-AB结构,并对后级的运放进行了缩放.采用栅压自举技术消除了低压下CMOS开关的开通电阻由于栅源电压变化而引起的非线性问题.整个调制器过采样率128.后仿结果表明,在SMIC 0.13μm CMOS MIX Signal工艺下,输入信号为2 kHz时该调制器在8 kHz信号带宽内,达到了92 dB的信噪失真比.在1 V电源电压下功耗仅为38μW.核心版图面积为0.25 mm2.A single-loop third-order switched-capacitor sigma-delta modulator for hearing aid application is presented. The OSR （over sampling ratio） is increased by using double-Sampling to improve the SNDR （signal noise distortion ratio） of the modulator. The effect of capacitance mismatch is detailed analyzed. Class-AB operation is also adopted in the OTA design to further decrease the power consumption. Boot-strapping is introduced to suppress nonlinear ON-resistance of CMOS switches under low-voltage due to the variation of gate voltage. The modulator achieves 92 dB SNDR in 8 kHz signal bandwidth with an OSR of 128. The power consumption is 38 μW under 1 V supply voltage and the chip core area is 0. 25 mm^2 .

关 键 词：双采样 ∑△调制器 低压低功耗 

分 类 号：TN432[电子电信—微电子学与固体电子学]