一种高精度单环高阶Σ-Δ调制器

设计了一种高精度单环3阶Σ-Δ调制器。阐述了Σ-Δ调制器的结构,确定了前馈因子和增益因子等重要参数。对调制器的各种非理想因素,如时钟抖动、开关非线性、采样电容kT/C噪声等,进行了量化分析和行为级建模。采用MATLAB工具进行了系统验证。验证结果表明,调制器的采样频率为100 kHz,信噪比为99 dB,信噪比最大值为104.2 dB,有效精度达16 位。     

低电压Σ-Δ调制器关键技术及设计实例

介绍了低电压开关电容Σ-Δ调制器的实现难点及解决方案,并设计了一种1 V工作电压的Σ-Δ调制器.在0.18 μm CMOS工艺下,该Σ-Δ调制器采样频率为6.25 MHz,过采样比为156,信号带宽为20 kHz;在输入信号为5.149 kHz时,仿真得到Σ-Δ调制器的峰值信号噪声失真比达到102 dB,功耗约为5 mW.     

用于过采样Σ-ΔA/D转换器的Σ-Δ调制器

分析并讨论了过采样 Σ- Δ A/D转换器中一阶、二阶及高阶级联结构的 Σ- Δ调制器的性能特点 ,并编写 C语言程序进行行为级仿真 ,用 PSpice进行电路级仿真 ,利用 MATLAB工具对其结果进行分析。结果表明 ,Σ-Δ调制器具有噪声整形特性 ,可以提高基带内的信噪比 ,且三阶级联结构中 1 - 1 - 1结构性能最优。Σ- Δ调制器与过采样技术相结合可构成高精度、低成本的 A/D转换器。     

一种低电压工作的高速开关电流Σ-Δ调制器

基于作者先前提出的时钟馈通补偿方式的开关电流存储单元及全差分总体结构,本文设计了一种二阶开关电流Σ-Δ调制器.工作中采用TSMC 0.35μm CMOS数字电路工艺平台,在低电压工作下进行电路参数优化.实验表明,调制器在3.3V工作电压、10MHz采样频率、64倍过采样率下实现10-bit精度.与已有类似研究相比,本工作在相当的精度条件下,实现了低电压、视频速率的工作.     

1.8V音频Σ-Δ调制器的设计

介绍了一种适用于语音信号处理的16位24 kHzΣ-Δ调制器。该电路采用单环三阶单比特量化形式,利用Matlab优化调制器系数。电路采用SIMC 0.18μm CMOS工艺实现,通过Cadence/Spectre仿真器进行仿真。仿真结果显示,调制器在128倍过采样率时,带内信噪比达到107 dB,满足设计要求。     

一种单环Δ-Σ调制器的全数字实现

针对无线人体局域网(WBAN),采用TSMC 0.18 μm CMOS工艺,对3阶单环结构Δ-Σ调制器进行了优化设计和全数字实现。实验结果表明,在Δ-Σ调制器中使用Qn方法实现对浮点小数的定点化,优化后的结构能够在运算精度、器件尺寸及功耗上达到平衡。该研究工作可以为实现全数字小数锁相环提供重要的理论及设计参考。     

一种单环Δ-Σ调制器的全数字实现

针对无线人体局域网(WBAN),采用TSMC 0.18μm CMOS工艺,对3阶单环结构Δ-Σ调制器进行了优化设计和全数字实现。实验结果表明,在Δ-Σ调制器中使用Qn方法实现对浮点小数的定点化,优化后的结构能够在运算精度、器件尺寸及功耗上达到平衡。该研究工作可以为实现全数字小数锁相环提供重要的理论及设计参考。     

一种带斩波的双采样Σ-Δ调制器

设计了一种适用于过高磁场抗扰度的电容式隔离型全差分Σ-Δ调制器。它采用单环2阶1位量化的前馈积分器结构,运用斩波技术降低低频噪声和直流失调。与传统的全差分结构相比,该调制器的每级积分器均采用4个采样电容,在一个时钟周期内能实现两次采样与积分,所需的外部时钟频率仅为传统积分器的一半,降低了运放的压摆率及单位增益带宽的设计要求,实现了低功耗。基于CSMC 0.35 μm CMOS工艺,在5 V电源电压、10 MHz采样频率和256过采样率的条件下进行电路仿真。后仿真结果表明,调制器的SNDR为100.7 dB,THD为－104.9 dB,ENOB可达16.78位,总功耗仅为0.4 mA。     

一种具有改进积分器结构的高阶Σ-Δ调制器

设计了一个五阶单回路Σ-Δ调制器,最高输入信号频率22kHz。通过改进积分器的结构,显著减小了开关电荷注入效应引起的调制器的谐波失真。整个电路采用0.6μmCMOS工艺设计。仿真显示,当采样频率为6MHz时,调制器的SNDR达到123dB,SNR超过125dB,满足18位A/D转换器的精度要求。     

信号的低比特位数表示:一种新颖低比特位数的Σ-Δ调制器

通过设计一种新的噪声整形滤波器,本文提出了一种新颖的Σ-Δ调制器结构,可用于实现用较低比特位数的数字信号表示较高比特位数的输入信号.该调制器与传统的Σ-Δ调制器相比,其输出数字信号比特位数(或动态范围)降低了许多.理论推导分析和仿真对比的结果表明,在量化噪声整形和噪声频谱上,该调制器的各项性能有了很大的提高,而且证明了这类调制器是稳定的.     

一种用于微机械惯性传感器中的16位ΣΔ调制器

A fourth-order low-distortion low-pass sigma-delta （∑△） modulator is presented for micro-machined inertial sensors. The proposed single-loop single-bit feedback modulator is optimized with a feed-forward path to decrease the nonlinearities and power consumption. The IC is implemented in a standard 0.6 μm CMOS technology and operates at a sampling frequency of 3.846 MHz. The chip area is 2.12 mm^2 with 23 pads. The experimental results indicate a signal-to-noise ratio （SNR） of 100 dB and dynamic range （DR） of 103 dB at an oversampling rate （OSR） of 128 with the input signal amplitude of-3.88 dBFS at 9.8 kHz; the power consumption is 15 raW at a 5 V supply.     

80dB动态范围，用于低中频结构GSM接收机的ΣΔ调制器

介绍了一个200kHz信号带宽、用于低中频结构GSM射频接收机的高精度ΣΔ调制器.该调制器采用3阶单环单比特的结构,电路使用全差分开关电容结构实现,并在0.6μm 2P2M CMOS工艺下流片验证.调制器使用全差分±1V参考电压,工作在26MHz采样频率,过采样率为64.测试结果表明,在200kHz信号带宽内,调制器达到80.6dB动态范围,峰值SNDR达到71.8dB,峰值SNR达到73.9dB.整个调制器电源电压为5V,静态功耗为15mW.     

80dB动态范围,用于低中频结构GSM接收机的∑△调制器

介绍了一个200kHz信号带宽、用于低中频结构GSM射频接收机的高精度∑△调制器.该调制器采用3阶单环单比特的结构,电路使用全差分开关电容结构实现,并在0.6μm 2P2M CMOS 工艺下流片验证.调制器使用全差分±1V参考电压,工作在26MHz采样频率,过采样率为64.测试结果表明,在200kHz信号带宽内,调制器达到80.6dB动态范围,峰值SNDR达到71.8dB,峰值SNR达到73.9dB.整个调制器电源电压为5V,静态功耗为15mW.     

应用于脑电监控的低功耗开关电容Delta-Sigma调制器

本文介绍了一个应用于便携式脑电监控生物医学系统的三阶单环Delta-Sigma调制器。为了降低功耗,调制器中的环路滤波器采用开关电容电路实现。调制器在0.35-μm 2P4M标准CMOS工艺下流片。核心面积为365×290μm2。实验结果显示,输入100Hz的正弦波,在64倍过采样率下,调制器能达到68dB的动态范围。供电电压为2.5V,整个芯片消耗515μW的功耗。适用于便携脑电监控系统。     

84dB动态范围13b/400kHz/3V/5.88mW ΣΔ模数转换器

介绍了一个200kHz信号带宽、用于低中频结构GSM射频接收机的高精度ΣΔ调制器. 为了达到高线性和稳定性,调制器采用2-1级联单比特的结构实现. 电路在0.18μm CMOS工艺下流片验证,核心面积为0.5mm×1.1mm. 调制器工作在19.2MHz的采样频率,在3V电源电压下功耗为5.88mW. 测试结果表明,在200kHz信号带宽,过采样率为64的条件下,调制器达到84.4dB动态范围,峰值SNDR达到73.8dB,峰值SNR达到80dB.     

Digital Technique for Instability Detection and Saturation Recovery in High-Order SC ΣΔ Modulators

Stability and saturation recovery are a key concern in High-order Switched Capacitor (SC) modulators, since they are conditionally stable architectures.A novel digital technique, which allows to detect instability in the digital domain, a fast recover of high-order modulators from instability and guarantees a minimum of Signal-to-Noise Ratio (SNR) also when the architecture gets unstable, is proposed. This technique operates in two steps: first, the instability is detected in the digital domain and the system is recovered to a proper operation and then a digital post-processing is performed in order to achieve a residual SNR also in the instability condition.This strategy has been applied to a 6th-order SC bandpass modulator operating at 42.8 MHz and featuring 74 dB Dynamic Range (DR) in a 200 kHz bandwidth. The benchmark modulator has been integrated in a standard double-poly 0.35 m 3.3 V CMOS technology with five metal layers.     

84dB动态范围13b/400kHz/3V/5.88mW∑△模数转换器

介绍了一个200kHz信号带宽、用于低中频结构GSM射频接收机的高精度∑△调制器.为了达到高线性和稳定性,调制器采用2-1级联单比特的结构实现.电路在0.18μm CMOS工艺下流片验证,核心面积为0.5mm×1.1mm.调制器工作在19.2MHz的采样频率,在3V电源电压下功耗为5.88mW.测试结果表明,在200kHz信号带宽,过采样率为64的条件下,调制器达到84.4dB动态范围,峰值SNDR达到73.8dB,峰值SNR达到80dB.     

A Triple-Mode Sigma-Delta Modulator for Multi-Standard Wireless Radio Receivers

A 1.8 V sigma-delta modulator with a 4 bit quantizer has been designed for GSM/WCDMA/WLAN receivers in a 0.18 um CMOS process. The modulator makes use of low-distortion sigma-delta modulator architecture and Pseudo-Data-Weighted-Averaging technique to attain high linearity over a wide bandwidth. Power dissipation is minimized by optimizing the architecture and by a careful design of analog circuitry. In GSM mode, the modulator achieves 96/104 dB peak SNR/SFDR over 100 kHz bandwidth and dissipates 18 mW at a sampling frequency of 32 MHz. The modulator achieves 92/68 dB peak SFDR and 77/54 dB peak SNR over a 2 MHz/10 MHz bandwidth and dissipates 23/39 mW at a sampling frequency of 64 MHz/160 MHz in WCDMA/WLAN. Ana Rusu received degrees of diploma engineer in electronics and telecommunications engineering from Technical University of Iasi, Romania, in 1983 and Ph.D. in electronics engineering from Technical University of Cluj-Napoca, Romania, in 1998. During 1983–1986 she was with Research Institute for Electronics Iasi, as researcher engineer. From 1986 to 1988 she was with Territorial Computer Centre, Piatra-Neamt, Romania, as a programmer in software engineering. Since 1988 she has been with the Technical University of Cluj-Napoca, Electronics and Telecommunications Faculty. In 1999 she was appointed as an associate professor. She has been in visiting researcher positions in University of Bradford, England, and Institute National Politechnique of Grenoble, France, in 1997 and 2001, respectively. Since September 2001, she has been with the Royal Institute of Technology (KTH), Stockholm, Sweden, where she is a senior researcher in radio and mixed-signal systems group. Her research interests include data conversion techniques for wireless communications and the design of low-voltage low-power analog and mixed-signal ICs. Ana Rusu has authored or coauthored five books (published in Romanian language) and more than 40 papers in international conference proceedings and journals. Alexey Borodenkov received his B.Sc. degree in computer science and engineering from St. Petersburg Electrotechnical University, Russia in 2002 and M.Sc. degree in electrical engineering from Royal Institute of Technology (KTH), Stockholm, Sweden in 2004. In October 2004 he joined Samsung Electronics Co. Ltd., Gyeunggi-Do, Korea, where he is involved in the design of multi-standard transceivers for wireless communications. His current research interests include integrated-circuit development of frequency synthesizers and data converters. Mohammed Ismail received the B.S. and M.S. degrees in electronics and telecommunications engineering from Cairo University, Egypt, in 1974 and 1978 and the Ph.D. in electrical engineering from the University of Manitoba, Canada, in 1983. He is a Professor with the Department of Electrical Engineering, The Ohio State University, Columbus. Since April 2003, he is also a Professor with the Department of Microelectronics and Information Technology, Royal Institute of Technology (KTH) Stockholm, Sweden. He has over 20 years experience of R&D in the fields of analog, RF and mixed signal integrated circuits. He has held several positions in both industry and academia and has served as a corporate consultant to nearly 30 companies in the US, Europe and the Far East. His current interest lies in research involving digitally programmable/configurable fully integrated radios with focus on low voltage/low power first-pass solutions for 3G and 4G wireless handhelds. He publishes intensively in this area and has been awarded 11 patents. He has co edited and coauthored several books. He co-founded ANACAD-Egypt (now part of Mentor Graphics, Inc.) and Spirea AB, Stockholm (now Firstpass Semiconductors AB), a developer of CMOS radio and mixed signal IPs for handheld wireless applications. Dr. Ismail has been the recipient of several awards including the US National Science Foundation Presidential Young Investigator Award, the US Semiconductor Research Corp Inventor Recognition Awards in 1992 and 1993, and a Fulbright/Nokia fellowship Award in 1995. He is the founder of the International Journal of Analog Integrated Circuits and Signal Processing, Springer and serves as the Journal's Editor-In-Chief. He has served as Associate Editor for many IEEE Transactions, was on the Board of Governors of the IEEE Circuits and Systems Society and is the Founding Editor of “The Chip” a Column in The IEEE Circuits and Devices Magazine. He is a Fellow of IEEE. Hannu Tenhunen received degrees of diploma engineer in electrical engineering and computer sciences from Helsinki University of Tehnology, Helsinki, Finland, in 1982 and Ph.D. in Microelectronics from Cornell University, Ithaca, NY, U.S.A., in 1986. During 1978–1982 he was with Electron Physics Laboratory, Helsinki University of Technology, and from 1983 to 1985 at Cornell University as a Fullbright scholar. From September 1985 he has been with Tampere University of Technology, Signal Processing Laboratory, Tampere, Finland, as an associate professor. He was also a coordinator of National Microelectronics Program of Finland during 1987–1991. Since January 1992, he has been with Royal Institute of Technology (KTH) Stockholm, Sweden, where he is a professor of electronic system design. His current research interests are VLSI circuits and systems for wireless and broadband communication, and related design methodologies and prototyping techniques. He has made over 400 presentations and publications on IC technologies and VLSI systems worldwide, and has over 16 patents pending or granted.