用于高速ADC的低抖动时钟稳定电路

介绍了一种用于高速ADC的低抖动时钟稳定电路.这个电路由延迟锁相环(DLL)来实现.这个DLL有两个功能:一是通过把一个时钟沿固定精确延迟半个周期,再与另一个沿组成一个新的时钟来调节时钟占空比到50%左右;二是调节时钟抖动.该电路采用0.35 μm CMOS工艺,在Cadence Spectre环境下进行仿真验证,对一个8 bit、250 Msps采样率的ADC,常温下得到的时钟抖动小于0.25 ps rms(典型的均方根).     

一种新型差分脉宽控制环路的设计

设计了一种新型时钟稳定电路～差分脉宽控制电路.用参考电路产生参考电压,避免因采用环形振荡器等方法产生大的时钟抖动.同时,在控制电路部分用交叉耦合正反馈来调节时钟占空比.该电路采用0.18 μm工艺,电源电压为1.9 V,输入时钟占空比调节范围为25%～75%,时钟频率为2 GHz,时钟抖动小于200 fs.     

非常见问题解答 来自ADI公司的电话记录中奇怪但真实的故事

正消除模数转换器的时钟抖动问题:我该如何改进系统时钟或时钟电路以降低抖动?回答:时钟信号上的抖动或噪声只有在ADC时钟输入的阈值附近时,才能影响ADC的时序。提高     

可调节型低抖动时钟占空比稳定电路的设计

介绍了一种用于高速流水线ADC双沿采样的时钟占空比稳定电路。在传统占空比稳定电路的基础上,增加含连续时间积分器的反馈环路,并设计了时钟周期检测电路,同时可通过SPI配置积分器的参考电压,在片外调节芯片制造过程中产生的误差,并在前端增设一个高增益带宽时钟放大器,用来放大幅度很小(Vp-p100mV)的差分输入时钟信号。电路采用0.18μm 1.8V 1P5MCMOS工艺,可对频率范围为50~250MHz、占空比范围为10%~90%的输入时钟进行稳定调节,时钟峰-峰值抖动约为0.3ps@250MHz。     

可调节型低抖动时钟占空比稳定电路的设计

介绍了一种用于高速流水线ADC双沿采样的时钟占空比稳定电路。在传统占空比稳定电路的基础上,增加含连续时间积分器的反馈环路,并设计了时钟周期检测电路,同时可通过SPI配置积分器的参考电压,在片外调节芯片制造过程中产生的误差,并在前端增设一个高增益带宽时钟放大器,用来放大幅度很小(Vp-p<100 mV)的差分输入时钟信号。电路采用0.18 μm 1.8 V 1P5M CMOS工艺,可对频率范围为50~250 MHz、占空比范围为10% ~ 90%的输入时钟进行稳定调节,时钟峰-峰值抖动约为0.3 ps @ 250 MHz。     

一种用于高速高精度A/D转换器的时钟稳定电路

设计了一种完全满足高速高精度流水线A/D转换器的时钟稳定电路.通过在延迟环路中加入启动电路,使环路能在小于300 ns内快速锁定占空比,锁定精度为50%±1%.拥有20%～80%的占空比输入,且能很好地抑制外部时钟抖动,时钟抖动小于100 fs.电路采用0.35 μm工艺制作,芯片面积为0.5 mm×0.3 mm,在3.3 V电源电压下,功耗小于78 mW.     

一种高速低抖动四相位时钟电路的设计

超高速A/D转换器对精准的时钟电路提出严格要求,时钟抖动是影响其精度的重要因素。文章在分析时钟抖动对A/D转换器的影响后,介绍了一种适用于GHz的低抖动四相位时钟电路。电路采用时钟恢复电路、四相位分布网络和相位校正电路,得到占空比稳定、相位误差小的四相位时钟。采用0. 18μm CMOS工艺实现,电路仿真表明,四相位输出时钟抖动102 fs,占空比调整范围30%～70%,功耗277 mW@1. 8 V。     

一种基于全差分积分器的时钟稳定电路设计

设计了一种用于超高速A/D转换器的时钟稳定电路。利用全差分连续时间积分器将差分时钟信号的占空比量化为电压信号,再通过跨导放大器产生控制电流来调整输出时钟的共模电平,达到调整输出时钟占空比的目的。电路采用0.18 μm标准CMOS工艺进行设计,工作电压为1.8 V,在2 GHz的最高时钟频率下,将占空比为20%~80%的输入时钟信号调整为(50±1)%,输出时钟抖动小于132 fs,具有抑制时钟抖动的能力。     

1.25Gbps串并并串转换接收器的低抖动设计

对1.25Gbps应用于千兆以太网的低抖动串并并串转换接收器进行了设计,应用了带有频率辅助的双环时钟数据恢复电路,FLL扩大了时钟数据恢复电路的捕捉范围。基于三态结构的鉴频鉴相从1.25Gbps非归零数据流中提取时钟信息,驱动一个三级的电流注入环形振荡器产生1.25GHz的低抖动时钟。从低抖动考虑引入了均衡器。该串并并串转换接收器采用TSMC0.35μm2P3M3.3V/5V混合信号CMOS技术工艺。测试结果表明了输出并行数据有较好的低抖动性能:1σ随机抖动(RJ)为7.3ps,全部抖动(TJ)为58mUI。     

用于CDR电路的相位插值选择电路设计

时钟数据恢复电路是高速多通道串行收发系统中接收端的关键电路,其性能的优劣直接影响了整个系统的功能.描述了双环时钟数据恢复电路利用相位正交的参考时钟进行工作的原理,分析了传统的正交时钟产生方案,提出一种新的相位插值-选择方案并给出了CMOS电路实现.在SMIC 0.18 μm CMOS工艺下采用Cadence公司的仿真工具Spectre进行了晶体管级验证,结果显示,利用该电路恢复出来的时钟对数据进行重定时,能较好地消除传输过程中积累的抖动,有效地提高了输入抖动容限.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks