一种新型混合信号时钟延时锁定环电路设计

给出了数字时钟管理器(DCM)中的一种新型时钟延时锁定环电路(Clock Delay Locked Loop)的设计,为高速同步数据采集系统提供可靠的时钟解决方案。该电路设计是基于延时锁定环(DLL)原理上,采用混合信号电路设计方案来实现。设计中的数字电路控制模块,通过对改进后的电荷泵中的附加开关工作时间的精确控制来实现对输入时钟信号所需延时的精确控制,从而得到所需的延时。该电路不会累积相位误差,具有良好的噪声敏感度。电路采用0.18μm的CMOS工艺,工作电压1.5V,可管理的时钟信号最高频率为360MHz,延时范围为1T,延时精度为T/32。     

一种用于FPGA的270MHz到1.5GHz可重构多功能锁相环时钟发生器

本文设计实现了一种用于FPGA芯片的可重构多功能的锁相环时钟发生器。该时钟发生器具有可配置的时钟发生和延时补偿两种模式,分别实现时钟倍频和相位对准的功能。输出时钟信号还具有可编程的相移和占空比调节等高级时钟变化功能。为了提高相位对准和相移的精度,本文设计了一种具有新的快速起振技术的压控振荡器。本文还提出了一种延时分割方法以提高用于实现相移和占空比调节功能的后端分频器的速度。整个时钟发生器使用0.13μm标准CMOS工艺设计制作。测试结果表明,能够实现270MHz到1.5GHz的宽调节范围,当锁定在1GHz时,整个电路功耗为18mW,rms抖动小于9ps,锁定时间为2μs左右。     

一种用于产生多相时钟的延时锁定环

分析并实现了一种用于产生多相时钟的延时锁定环电路。利用重复延时线和周期检测器,避免了复位信号和错误锁定的问题;采用信号路径对称的鉴相器,减小了抖动;使用电流舵技术,提高了电荷泵的开关速度。基于SMIC 0.18μm CMOS工艺,实现了一种产生32相时钟的延时锁定环,芯片核心尺寸为0.7mm×0.55mm,参考时钟频率范围为20~150MHz。仿真结果显示,在输入参考时钟频率为60MHz时,最长锁定时间为1.9μs,抖动为1ps,1.8V电源电压下的功耗为31.5mW。     

一种用于高速流水线ADC的数字延迟锁相环电路

给出了一种应用于高速流水线A/D转换器的数字延迟锁相环电路.该电路的锁定过程采用顺序查找算法,设计了锁定检测窗口,用来判断延迟后的输出时钟信号是否满足锁定条件,根据检测结果即时调整延时大小,能有效避免误锁现象,准确完成延迟锁相功能.该数字延迟锁相环采用SMIC 0.18 μm 1.8 VCMOS工艺实现,频率范围为40～250 MHz.在输入最大频率下,仿真的锁定时间约为690 ns,抖动约为1.5 ps.     

一种用于锁相环快速锁定的动态鉴频鉴相器

设计了一种用于电荷泵锁相(CPPLL)快速锁定的动态鉴频鉴相器(PFD).该PFD采用传统结构,利用开关延时动态D触发器预充电,复位时间内输入时钟边沿未发生丢失,有效地消除了盲区.基于TSMC 0.18μm CMOS工艺,用Cadence Spectre对其进行仿真验证.结果显示,采用新型PFD的锁相环,其锁定速度提高40.3%,频率范围达1 MHz～2 GHz.     

数字控制可编程延时单元设计技术研究

提出一种数字控制可编程延时单元(Digitally Controlled Programmed Delay Element,DCPDE)结构,对数字控制字可编程延时单元(DCPDE)进行了理论分析和设计方法研究。采用二进制编码控制的电流镜为延时单元提供充、放电电流,实现了信号的上升、下降沿等量延时,本单元可嵌入全数字控制的延时锁定环设计中,能够实现50%占空比420ps～920ps的双沿延时。     

CMOS数字锁相环中的自校准技术

提出了一种数字锁相环(DPLL).该电路采用自校准技术,具有快速锁定、低抖动、锁定频率范围宽等优点.设计的锁相环在1.8 V外加电源电压时,工作在60～600 MHz宽的频率范围内.电路采用5层金属布线的0.18 μm CMOS工艺制作.测试结果显示,电路的峰-峰抖动小于输出信号周期(Tout)的0.5%,锁相环锁定时间小于参考时钟预分频后信号周期(Tpre)的150倍.     

全数字延时锁定环及其应用

介绍了一种区别于锁相环(PLL)和基于压控延迟线(VCDL)的延时锁定环(DLL)、全部由纯数字电路实现的DLL电路.该电路用于消除时钟时延,全数字的结构使其无条件稳定,不会累积相位误差,而且具有良好的噪声敏感度、较低的功耗和抖动性能.使其在时延补偿和时钟调整的应用中具有优势,并可全部嵌入单个芯片中.文中分析了全数字DLL的工作原理及其结构,给出了其在现场可编程门阵列(FPGA)中的应用.     

ADPLL数学建模与设计实现

全数字锁相环(ADPLL)与混合信号锁相环相比,具有功耗低、面积小、锁定时间短和易于移植等优点.提出了一种新的全数字锁相环结构,建立了该锁相环的系统级数学模型,通过Matlab仿真验证了系统的可行性,并用非线性理论证明了该系统的稳定性.并用建立的系统结构实现了ADPLL的电路版图,电路版图经0.13 μm工艺流片验证,实现了输入为2～25 MHz、输出为25～500 MHz的全数字锁相环电路样品.     

一种应用于图像传感器的全数字锁相环设计

针对图像传感器中传统锁相环(PLL)存在的功耗高、抖动大,以及锁定时长等问题,提出了一种基于计数器架构的低功耗、低噪声、低抖动、快速锁定的分数分频全数字锁相环(ADPLL)设计方法。首先,采用动态调节锁定控制算法来降低回路噪声,缩短锁定时间。其次,设计了一个通用单元来实现数字时间转换器(DTC)和时间数字转换器(TDC)的集成,以降低该部分由于增益不匹配引起的抖动。基于180nm CMOS工艺的仿真结果表明,在1.8V电源电压下,该ADPLL能够实现250MHz~2.8GHz范围的频率输出,锁定时间为1.028μs,当偏移载波频率为1MHz时,相位噪声为-102.249dBc/Hz,均方根抖动为1.7ps。     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

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正Communications—VLSI Researches and industries of telecommunications have been growing rapidly in the last 20 years and will keep their high growing pace in the next decade.The involved researches and developments cover mobile communications,highway and last-mile broadband communication,domain specific communications,and emerging D2D M2M communications.Radio communication steps into its