CMOS数字热真空传感器芯片设计

基于标准CMOS工艺设计了一款集成热真空传感器、运算放大器、逐次逼近型模数转换器(SAR ADC)、数字信号处理电路的传感器系统。工作在恒电流模式的传感器,气压敏感区间为1～105Pa。运算放大器(OPAMP)的输入级采用互补差分对获得轨至轨的共模输入范围。为满足精度要求,对SAR ADC中数模转换器电容阵列进行优化设计,并采用输出失调存储技术消除比较器的失调电压。数字电路采用查表法将电压信号变换为气压值。结果表明:运算放大器能无失真地驱动200Ω电阻,模数转换器的有效位为9.5 bit。运算放大器、模数转换器、数字信号处理电路性能良好,满足传感器系统要求。     

用于射频系统的10 MS/s 10位SAR A/D转换器

设计了一种用于射频系统的低功耗、中速中精度差分输入逐次逼近型(SAR)A/D转换器。采样完成后采用下极板对接的逻辑算法,10位SAR A/D转换器只需9位DAC即可满足其精度要求。DAC阵列采用分段电容结构,节省了芯片面积。比较器采用前置运算放大器加锁存器的结构,达到了同时兼顾速度和精度的要求。该A/D转换器芯片采用GSMC 0.13 μm 1P7M CMOS工艺制造,其核心电路尺寸为500 μm×360 μm,采用1.2 V的单电源供电。测试结果表明,当采样频率为10 MS/s,输入信号频率为2 MHz时,该SAR A/D转换器达到8.45位的有效精度,总功耗为2.17 mW;当采样频率为5 MS/s,输入信号频率为1 MHz时,该SAR A/D转换器达到8.75位的有效精度,总功耗为2.07 mW。     

一种高精度宽量程电阻测试仪的研制

提出利用恒压源和运算放大器将被测电阻阻值转化为电压实现电阻的测量方法,电压采用12位串行A/D转换器实现高精度转换,根据测试数据范围采用不同修正量、固定函数进行数据处理,从而实现高精度、宽量程的电阻测量。     

数字机无伴音故障的检修

电视屏幕上图像正常,出现无伴音和广播的故障,说明数字机的信号接收、解复用和解码均正常,视频编码器及其滤波网络都能正常工作,故障发生在音频D/A转换器及其后续的运算放大器上。大多数数字机的音频D/A转换器都采用PCM1723E,因此容易检修。若声音全无,则可能是音频D/A转换器损坏,可用示波器测量音频D/A转换器的左、右声道输出,无音频信号输出则说明音频D/A转换器损坏。若声音很小,则可能是运算放大器(通常为JR4558)损坏,或运算放大器周围的电阻、电容损坏。     

10位100 MHz CMOS流水线A/D转换器

介绍了一种10位100 MS/s流水线A/D转换器的设计方法,采用增益提升技术,实现了增益为100 dB和单位增益带宽为1.2 GHz的高性能跨导运算放大器.改进了系统的延时单元,能够准确地锁存输出信号,减少噪声的影响.仿真结果表明,整个系统的有效位数提高了0.5位.整个系统基于TSMC 0.18 μm CMOS工艺进行仿真,结果表明,整个电路的各个工艺角在温度为-20℃～85℃下均能满足100 MHZ采样率流水线A/D转换器的要求.     

一种用于16位Σ-Δ A/D转换器的跨导放大器

介绍了一种采用0.5μm CMOS工艺的轨到轨输入共栅共源带输出阻抗增强结构的跨导放大器电路。该放大器用在一个8倍过采样率,输出速率500 kps的16位二阶Σ-Δ加流水线型结构的A/D转换器中,位于Σ-Δ环路的第一级,完成过采样、相减求差和残差放大的功能,是整个A/D转换器的重要模拟电路单元。在5 V电源电压下,该放大器的仿真结果为直流增益大于90dB,单位增益带宽大于100 MHz,相位裕度大于75°。     

单片集成CMOS电阻真空传感器

设计了一种工作在恒电压模式的、微热板结构的单片集成电阻真空传感器芯片.提出了一种以CMOS集成电路中的介质层与钝化层为结构层、栅多晶硅为牺牲层、第二层多晶硅为加热电阻的微传感器单芯片集成工艺模式,制定了相应的工艺流程.采用0.6μm CMOS数模混合集成电路工艺,结合牺牲层腐蚀技术实现了单片集成真空传感器的加工,测试结果显示该芯片能够测量2～105Pa范围内的气压大小,且输出电压范围可调,验证了单片集成工艺的可行性.     

一种带双极性基准的双R-2R电阻网络结构

介绍了一种带双极性基准(±10 V)的双R-2R电阻网络结构。该结构充分利用双极性基准的优势,减少了双极性输出所需运算放大器的数量,提高了D/A转换器的精度;同时又降低了电路对工艺绝对精度的要求。经过理论推算和电路模拟仿真,在相同工艺精度条件下,采用该结构的12位D/A转换器,其精度优于其他两种采用常规双极性输出结构的D/A转换器。     

基于M-BUS总线的智能气压传感器的设计

基于M-BUS总线的智能气压传感器利用高精度气压传感器、24位A/D转换器AD7714、低功耗单片机P89LPC932完成对绝对气压的测量,并通过M-BUS总线向上位机传送测量结果。目前该仪器已在矿井风压自动监测报警系统中得到应用。     

单片集成CMOS电阻真空传感器

设计了一种工作在恒电压模式的、微热板结构的单片集成电阻真空传感器芯片.提出了一种以CMOS集成电路中的介质层与钝化层为结构层、栅多晶硅为牺牲层、第二层多晶硅为加热电阻的微传感器单芯片集成工艺模式,制定了相应的工艺流程.采用0.6μm CMOS数模混合集成电路工艺,结合牺牲层腐蚀技术实现了单片集成真空传感器的加工,测试结果显示该芯片能够测量2～10^5Pa范围内的气压大小,且输出电压范围可调,验证了单片集成工艺的可行性.     

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.     

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.     

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.     

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.