一种新的高精度电流/频率转换电路逻辑控制方法

电流/频率转换器主要是对加速度计输出电流进行高精度测量,典型展宽复位电荷平衡式电流/频率转换器的逻辑控制方法对精度影响较大.针对典型逻辑控制方法的不足,提出了一种新的逻辑控制方法.电路积分器输出通过一级D触发器作为比较电路实现模拟数字转换输出,然后通过二级D触发器和与门形成的自锁电路产生计数器启动触发脉冲,最后通过计数器电路计数形成开关控制逻辑.新方法避免了典型方法中对积分时间的约束,减小了大电流输入和小电流输入时积分器输出波形的平均值差异,从而有效提高了电路精度.对同一个硬件电路通过编写不同的CPLD算法程序进行性能对比测试,结果表明新的方法比典型的方法使电路精度得到明显提升.     

三值绝热多米诺文字运算电路开关级设计

通过对绝热多米诺电路和多值电路的研究,提出一种新颖的低功耗三值文字运算电路的开关级设计方案。该方案首先通过开关—信号理论推导出逻辑0和2的文字运算电路开关级结构式及电路;然后利用三种文字运算之间互斥与互补的约束关系得到逻辑1的文字运算输出信号,同时通过波形转换电路使电路的输出转换为较规则的缓变梯形波;最后利用Spice软件对所设计的电路进行仿真,结果显示所设计的三值绝热多米诺文字运算电路具有正确的逻辑功能,与常规多米诺三值文字运算电路相比,能耗节省约39%。     

基于局部逻辑伪装的IC保护方法

集成电路(IC)设计面临逆向工程的攻击,核心专利(IP)和算法被盗用,硬件安全受到威胁。该文提出一种电路伪装方法LPerturb,通过对其局部电路逻辑的扰动,实现IC电路的保护。对电路进行最大独立锥划分(MFFCs),选取被伪装的最大子电路,确保输出逻辑扰动的局部性。针对要扰动锥结点逻辑,从锥中选择被替换的逻辑单元,以最小化代价对进行局部电路逻辑扰动。用多值伪装电路对扰动的逻辑值进行混淆保护,恢复相应的电路逻辑。实验结果表明,该方法能够稳定生成保护电路,具有较好的输出扰动性,能有效抵御SAT去伪装攻击,面积额外开销较小,时延影响可以忽略。     

一种应用于AC-PDP开关电源的逻辑电压输出延时电路

根据AC-PDP电路系统的要求,分析了AC-PDP开关电源不同输出电压在开启和关闭时必须满足的时序要求,提出了一种新的应用于AC-PDP开关电源的逻辑控制电压输出延时电路,并通过实验验证了该电路的可行性.     

一种新型低噪声电流控制逻辑的分析与设计

本文绘出了一种新型电流控制逻辑的电路结构和工作原理，并由此提出了该逻辑的优化设计方法。通过采用恒定工作电流和限制电路的输出逻辑摆幅，电流控制逻辑能避免静态CMOS电路工作时引入的瞬态开关噪声电流。理论分析和电路模拟结果都表明，和静态CMOS电路相比，电流控制逻辑的峰值开关电流下降了近两个数量级．该逻辑可应用在高性能的模／数混合集成电路中。     

时钟产生电路中高频生成器的分析与设计

分析了目前常用的高频生成器的电路结构及其优缺点,提出了一种新的高频生成器电路结构.该电路完全由数字逻辑门构成,结构简单;同时,倍频系数可达10以上;在参考时钟频率为100 MHz时,可以实现1 GHz以上输出时钟的高频输出.     

基于局部逻辑伪装的IC保护方法

集成电路(IC)设计面临逆向工程的攻击,核心专利(IP)和算法被盗用,硬件安全受到威胁.该文提出一种电路伪装方法LPerturb,通过对其局部电路逻辑的扰动,实现IC电路的保护.对电路进行最大独立锥划分(MFFCs),选取被伪装的最大子电路,确保输出逻辑扰动的局部性.针对要扰动锥结点逻辑,从锥中选择被替换的逻辑单元,以最小化代价对进行局部电路逻辑扰动.用多值伪装电路对扰动的逻辑值进行混淆保护,恢复相应的电路逻辑.实验结果表明,该方法能够稳定生成保护电路,具有较好的输出扰动性,能有效抵御SAT去伪装攻击,面积额外开销较小,时延影响可以忽略.     

一种新型的抗DPA攻击可配置逻辑结构

DPA(Differential Power Analysis)攻击的强度取决于芯片电路功耗与所处理的数据之间的相关性以及攻击者对算法电路实现细节的了解程度.本文结合动态差分逻辑和可配置逻辑的特点,提出了一种具有抗DPA攻击能力的双端输出可配置逻辑(DRCL:Dual-Rail Configurable Logic)....     

基于与非锥的新型FPGA逻辑簇互连结构研究

该文针对新型FPGA可编程逻辑单元与非锥(And-Inverter Cone, AIC)的结构特性,提出一系列方案以得到优化的逻辑簇互连结构,包括:移除输出级交叉矩阵,单级反相交叉矩阵,低负载电路优化,将反馈和输出选择功能分开,限制AIC输出级数的基础上移除中间级交叉矩阵,与LUT架构进行混合等。通过大量的实验,得出针对面积延时积最优的AIC簇互连结构,与Altera公司的FPGA芯片Stratix-IV结构相比,该结构逻辑功能簇本身面积减小9.06%, MCNC应用电路集在基于优化的AIC FPGA架构上实现的平均面积延时积减小40.82%, VTR应用电路集平均面积延时积减小17.38%;与原有的AIC结构相比,簇面积减小23.16%, MCNC应用电路集平均面积延时减小27.15%, VTR应用电路集平均面积延时积减小15.26%。     

高精度宽范围数控电流源模块设计

文章设计并制作了一个高精度宽范围数控电流源模块,该模块由逻辑控制电路、D/A转换电路、压控恒流源电路和电压监测保护电路组成,采用可编程逻辑解析处理器的控制字,经过D/A转换控制压控恒流源电路输出电流,同时输出电流通过采样电阻转换成电压送至A/D转换,并与预设值进行比较,以实现高精度、高量程的电流输出。设计的该电流源模块能够满足高精度航空电机的控制需求,具有控制精度高、输出范围宽,降低了设备的重量和体积等优点。     

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.     

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.     

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.     

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

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.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.