一种高共模抑制比轨到轨全差分运算放大器

针对传统全差分运算放大器电路存在输入输出摆幅小和共模抑制比低的问题,提出了一种高共模抑制比轨到轨全差分运算放大器电路。电路的输入级采用基于电流补偿技术的互补差分输入对,实现较大的输入信号摆幅;中间级采用折叠式共源共栅结构,获得较大的增益和输出摆幅;输出级采用共模反馈环路控制的A类输出结构,同时对共模反馈环路进行密勒补偿,提高电路的共模抑制比和环路稳定性。提出的全差分运算放大器电路基于中芯国际(SMIC) 0.13μm CMOS工艺设计,结果表明,该电路在3.3 V供电电压下,负载电容为5 pF时,可实现轨到轨的输入输出信号摆幅;当输入共模电平为1.65 V时,直流增益为108.9 dB,相位裕度为77.5°,单位增益带宽为12.71 MHz;共模反馈环路增益为97.7 dB,相位裕度为71.3°;共模抑制比为237.7 dB,电源抑制比为209.6 dB,等效输入参考噪声为37.9 nV/Hz^1/2@100 kHz。     

一种高性能共模反馈CMOS运算放大器

介绍了一种具有高增益,高电源抑制比(CMRR)和大带宽的两级共源共栅运算放大器。此电路在两级共源共栅运算放大器的基础上增加共模反馈电路,以提高共模抑制比和增加电路的稳定性。电路采用0.35μm标准CMOS工艺库,在Cadence环境下进行仿真。结果显示,该放大器增益可达到101 dB,负载电容为10 pF时,单位增益带宽大约为163 MHz,共模抑制比可达101dB,电路功耗仅为0.5 mW。     

两级运放中共模反馈电路的分析与设计

在两级共源共栅CMOS运算放大器中,设计了一种新的共模反馈电路。这种电路克服了一般共模反馈电路存在的限制输出摆幅的缺点,在稳定电路直流工作点的同时,能有效提高电路的输出摆幅。通过对共模电路结构的分析,证明了其功能原理的正确性。基于0.18μm(3V)CMOS工艺库,用Hspice软件对电路结构进行了仿真验证。结果显示,电路低频增益达到120dB,功耗不到0.24mW。     

一种带增益提高技术的高增益CMOS运算放大器的设计

给出了一种用在高速高精度流水线型模数转换器中的具有高增益和高单位增益频率的全差动CMOS运算放大器的设计,电路结构主要采用折叠式共源共栅结构,并采用增益提高技术提高放大器的增益。共模反馈电路由开关电容共模反馈电路实现。模拟结果显示,其开环直流增益可达到106 dB,在负载电容为2 pF时单位增益频率达到了167 MHz,满足了对模数转换器的高速度和高精度的要求。     

一种快速全差分CMOS运算放大器

文章在CSMC0．5μm／5V硅CMOS工艺模型下,设计了一种用于电表计量芯片的全差分运算放大器。该运放采用两级结构,其中第一级为折叠式共源共栅结构,第二级为PMOS输出缓冲结构。文章采用开关电容技术实现共模反馈以稳定输出共模电压,跟传统方法相比,这将能降低芯片面积及降低功耗。采用HSPICE软件对该电路进行仿真,仿真结果表明在负载电容为2pF情况下,该运算放大器具有开环增益为84．7dB、单位增益带宽达44．8MHz、相位裕度为67°、闭环小信号建立时间为39ns。     

一种高单位增益带宽CMOS全差分运算放大器

设计并讨论了一种高单位增益带宽CMOS全差分运算放大器。由于折叠共源共栅结构电路具有相对高的单位增益带宽以及开关电容共模反馈电路稳定性好、对运放频率特性影响小等优点,故设计的放大器采用了折叠共源共栅结构以及开关电容共模反馈电路技术,并达到了高单位增益带宽的设计目的。基于TSMC0·25μmCMOS工艺,仿真结果表明,在2·5V的单电源电压下,运算放大器的直流开环增益为70dB,单位增益带宽为500MHz。     

适用于高阶Sigma Delta调制器的全差分运算放大器的设计

比较了套筒式共源共栅、折叠式共源共栅和两级AB类输出的三种运算放大器结构,提出了一种可用于前馈型高阶Sigma Delta调制器的全差分跨导运算放大器.采用SIMC 0.18 μmCMOS工艺,完成了含共模反馈电路的两级AB类输出的跨导运算放大器的设计.利用Cadence/Spectre仿真器进行仿真,结果表明放大器的直流增益为62.19dB,单位增益带宽为205.56 MHz,相位裕度为70.81°,功耗仅为0.42 mW,适合于低压低功耗Sigma Delta调制器的应用.     

基于前馈gmf的共模反馈稳定性增强电路

基于0.13 μm CMOS工艺,提出并设计了一种应用于三级全差分运算放大器中的新型共模反馈电路。将具有密勒补偿结构的典型两级全差分结构和源随器结构作为三级运算放大器的放大级,通过在共模反馈电路中引入前馈通路,产生的两个零点提高运放的稳定性,解决了传统共模反馈电路中多个极点难以补偿的问题。仿真结果表明,在1.2 V电源电压下,共模下增益为70.4 dB,单位增益带宽为56 MHz,相位裕度为85.5°。相比于传统无前馈电路,新型共模反馈电路的单位增益带宽和相位裕度分别提高了8.2 MHz和17.4°。具有这种共模反馈结构的运算放大器可以实现较低的电源电压和较好的相位裕度。     

一种应用于开关电容电路的0.9 V自适应偏置OTA

设计了一种应用于开关电容电路的自适应偏置的低电压、低功耗开关运算跨导放大器。采用负阻负载技术和自适应偏置技术,分别提高了放大器的增益和转换速率;采用电流镜型OTA技术降低功耗,并通过控制开关关断非工作状态下的运放电源,进一步降低了功耗。新型开关电容共模反馈电路的共模电压可在一个时钟周期内快速稳定,不增加额外功耗,不限制输出摆幅。在SMIC 0.18 μm工艺下的仿真结果表明,OTA在0.9 V供电下,直流增益达60 dB,增益带宽积为1.81 MHz,转换速率为0.94 V/μs,功耗为4.16 μW。     

一种高增益、低功耗、Rail-to-Rail输出的BiCMOS运算放大器

文章介绍了一种基于0.6!mBiCMOS工艺,高增益、低功耗、RailtoRail输出的运算放大器。对运放进行了仿真分析,在外接10K电阻条件下该运放可达到115dB的直流开环电压增益,0.32mw的功耗;在100pF电容负载下,单位增益带宽为2.1MHz,相位裕度为60°;同时由于使用了共模反馈结构,使得运放获得了高的电源抑制比和共模抑制比。     

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.     

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.     

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.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.