一种高精度全集成50 MHz振荡器

设计了一种基于平均电压反馈技术的片上高精度全集成张弛振荡器,所设计的振荡器克服了传统张弛振荡器对比较器延迟、器件老化和电流源噪声等敏感的问题。此外,还设计了一种一次性自动频率校正电路,可使振荡器在外部参考时钟的辅助下,自动完成输出频率的高精度校准。采用UMC 40 nm CMOS工艺,实现了50 MHz高精度全集成张弛振荡器,并完成了振荡器的版图和后仿真。振荡器的版图面积为181μm×218μm。后仿真结果表明,所设计振荡器能在不同工艺角下将输出频率自动校准到50 MHz,且在供电电压从2.2 V到3.6 V、温度从-40℃到125℃的变化下,输出频率误差仅为±0.47%。典型工艺角下,振荡器功耗为200μW。     

一种基于比较器失配补偿的高稳定性RC振荡器

针对传统RC振荡器容易受到温度和工艺偏差影响的问题,提出了一种新的振荡器结构。该振荡器电路运用零温度系数参考电压和开关网络,实现了比较器电路的工艺失配补偿,达到了高的温度稳定性。该振荡器具有对温度和工艺偏差不敏感、面积小、功耗低等优点。仿真结果表明,输出时钟频率为11.5 kHz时,在-10℃~90℃温度范围内振荡器频率偏差在±1%以内。     

一种具有温度补偿的低功耗张弛振荡器

提出了一种具有温度补偿和数字修调的低功耗CMOS张弛振荡器。基于阈值电压和偏置电流的匹配技术实现输出频率的1阶温度补偿,保证输出频率在大温度范围内的高稳定性。采用数字修调技术,校正工艺偏差引起的频率偏差。因此,该振荡器的输出频率对温度、电源电压和工艺偏差不敏感。振荡器采用0.18 μm CMOS工艺进行设计,使用Cadence进行仿真验证。结果表明,在1.8 V电源电压下,消耗电流为400 nA;在－40 ℃~125 ℃温度范围内,输出频率变化小于±1%;在1.5~2.5 V电源电压变化范围内,频率偏差小于1%。     

一种基于开关电容的高精度低温度系数振荡器

在分析传统环形振荡器的基础上,提出了一种基于开关电容的高精度低温度系数环形振荡器。采用了带开关电容电路的频率负反馈架构,使得输出频率的精度与其温度系数仅取决于外部设定电阻与片上电容,通过合理选择外部设定电阻,即可实现高精度、低温漂的时钟输出。设计的高精度低温度系数的环形振荡器采用0.6 μm标准CMOS工艺设计。仿真结果显示,当输出频率为5 MHz时,输出频率误差≤1.74%,频率温度系数≤8.11×10-5/℃。     

一种幅频稳定的正弦信号发生器

提出了一种简易的正弦信号发生器结构,电路前级为一个频率稳定的张弛振荡器,后级为一个三角-正弦信号转换器,利用一种新颖的两级温度系数互补原理,获得了不随温度变化的稳定的输出幅度.该信号发生器工作在±15 V电源电压下,频率稳定性为98×10-6/℃,幅度稳定性0.05 μA/℃.该振荡器已成功集成到线性可变差动变压器(LVDT)的信号调理芯片中.     

一种工艺误差校准的低功耗温度传感器

采用一种新的张弛振荡器,实现了一种不受工艺影响的低功耗片上温度传感器。将与温度成正比的电流输入到振荡器,产生与温度成正比的频率,再利用计数器来实现频率到数字的转换。振荡器通过数字逻辑产生两种模式,分别控制受温度控制的振荡器(TDO)和对温度不敏感的振荡器(TIO),这两种模式只需1个振荡器和1个计数器,减小了面积和功耗。采取工艺粗校准和工艺精校准两步校准,减小了工艺偏差。实验结果表明,经过两步校准后,在-40 ℃到120 ℃范围内,温度传感器的分辨率为0.08 ℃/LSB,温度传感器的最大误差为+0.35 ℃/-0.6 ℃。在1.2 V电源电压、120 ℃温度的条件下,电路总功耗仅为23 μW。     

汽车电压调节器低频振荡电路的设计

针对汽车电压调节器,设计了一种受温度和电源电压变化影响很小的低频振荡器。通过采用正温度系数电流和负温度系数电流相互叠加,形成2阶补偿,以更加稳定的电流对电容进行充放电。在该振荡电路中,引入一个简单的参考电压电路,使电容充放电的电压随充放电电流的微小变化而变化,以实现电压对电流变化的补偿,从而更加有效地提高振荡器频率的稳定性。基于CSMC 40VBCD工艺,采用Spectre进行仿真,在5V电源电压、-40℃～160℃温度范围内,其频率最大误差小于0.96%;在4～6V电源电压下,温度为0℃时,其频率最大误差小于1.33%。     

一种带高阶温度补偿的片内时钟振荡器设计

本文基于0.18μm CMOS工艺,设计了一款适用于片上系统SoC的无需晶振的片内12MHz时钟信号产生电路。利用高阶温度补偿方案,该时钟振荡器能在较宽的温度范围内实现振荡频率的高稳定性。此外,电路的稳压器设计使得振荡器频率在电源电压变化时也能保持相当好的稳定性。仿真结果表明,在-40℃~125℃温度范围内,此振荡器振荡频率的温度系数仅为40ppm/℃,电源电压变化±10%时,振荡频率的相对误差仅为±0.012%,完全能够满足常规数字系统的要求。     

降压式DC-DC电源管理芯片中振荡器电路的设计与研究

文章为一款降压式DC-DC电源芯片提供一种高性能的振荡器电路以及斜坡发生器,并对其工作原理进行了分析。文章采用中芯国际0.18μm CMOS工艺,在Cadence软件下,利用specture电路仿真工具,对振荡器电路进行仿真。经过仿真验证,该电路振荡频率在3.3V,27℃的典型环境下,中心振荡频率为672.4 kHz,达到了预期指标,实现了电路功能。在温度-20℃～120℃的仿真条件下,振荡器的频率受温度影响非常小,性能稳定,频率偏移率为3.8%。     

一种具有高阶温度补偿的高精度RC振荡器设计

基于当前一些高集成度高精度应用领域时钟信号大量需求的目的，介绍了一种具有高阶温度补偿的高精度RC振荡器。文中所设计的电流源电路采用了3阶温度补偿的方法，可以有效降低电路对温度变化的敏感性，利用具有超低温度系数的电流对电容进行充放电，实现在较宽的温度范围内振荡器频率的高稳定性。仿真结果表明：在电源电压范围为2.5 V～5.5 V，温度范围为-40℃～125℃，及不同的工艺角下，输出频率精度保持在±0.25%以内。该RC振荡器具有高精度的输出频率，能够作为一些数模混合电路的时钟信号。     

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.     

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     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first