基于CLS技术的音频应用低功耗Δ-Σ调制器  

Low-Power Δ-Σ Modulator with CLS Technique for Audio Applications

作　　者：吴剑涵 黄恭兴 陈群超[1] 魏榕山[1] WU Jianhan;HUANG Gongxing;CHEN Qunchao;WEI Rongshan(College of Physics and Information Engineering,Fuzhou University,Fuzhou 350116,China)

机构地区：[1]福州大学物理与信息工程学院,福建福州350116

出　　处：《电视技术》2023年第3期17-22,共6页Video Engineering

基　　金：福建省技术创新重点攻关及产业化项目(2022G020)。

摘　　要：为了提高便携式音频产品的续航能力,设计一种三阶单环单比特前馈结构的离散时间Δ-Σ调制器。采用浮动反向放大器(Floating Inverter Amplifier,FIA)作为跨导放大器(Operational Transconductance Amplifier,OTA),可以降低整体电路的功耗,实现良好的鲁棒性,并且不需要额外的共模反馈电路。通过相关电平移位(Correlated Level Shifting,CLS)技术可以提高开关电容积分器的直流增益,来降低增益误差。该Δ-Σ调制器采用SMIC 0.18μm CMOS工艺实现,后仿结果表明,在4 MHz的采样频率和1.2 V的电源电压下,实现了88.81 dB的信号噪声失真比(Signal-to-Noise-and-Distortion Ratio,SNDR),14.46 bit的有效位数(Effective Number of Bits,ENOB),99.157 dB的动态范围(Dynamic Range,DR),功耗仅98.676μW。To improve the battery life of portable audio products,a discrete time delta-sigma modulator with a third-order single-loop single-bit feedforward structure was designed.A Floating Inverter Amplifier(FIA)-based Operational Transconductance Amplifier(OTA)was proposed to reduce the power consumption of the overall circuit,and achieved good robustness without an additional common-mode feedback circuit.The DC gain of switched-capacitor integrator could be improved by Correlated Level Shifting(CLS) technique to reduce the gain error.The Δ-Σ modulator was implemented on SMIC 0.18μm CMOS process.The post-simulation results showed that it achieved 88.81 dB Signal-to-Noise-and-Distortion Ratio(SNDR),14.46 bit Effective Number of Bits(ENOB) and 99.157 dB Dynamic Range(DR) with a 4 MHz sampling frequency and a 1.2 V supply voltage consuming only 98.676 μW.

关 键 词：音频应用 Δ-Σ调制器 低功耗 浮动反向放大器 相关电平移位 

分 类 号：TN761[电子电信—电路与系统]