用于相变存储器的超低输出纹波2X/1.5X电荷泵

本文针对相变存储器编程驱动电路,提出了一种超低输出电压纹波的开关电容型电荷泵。该电荷泵可根据输入电压的不同,自适应工作在2X/1.5X升压模式之间,以获得更高的电源转换效率。相比于传统开关电容型电荷泵,在充电阶段泵电容被充电至预先设定的电压值Vo-VDD(Vo为预期的输出电压);放电阶段,泵电容串联在输入电压VDD与输出端,通过此方法将电荷泵输出端电压稳定在Vo,并有效的降低了由于电荷分享所造成的输出纹波。在中芯国际40nm标准CMOS工艺模型下,对电路进行了仿真验证,结果表明在输入电压为1.6-2.1V,输出2.5V电压,最大负载电流为10mA,输出电压纹波低于4mV,电源效率最高可达91%。     

基于电荷泵的倍增/反向双输出电压转换设计与实现

为了解决目前基于电荷泵的开关电容电压转换芯片功能较为单一的问题,基于Dickson经典电荷泵结构,匹配四路双极型晶体管开关同时实现对输入电压的倍增输出以及倍增后的电压反向。四路二极管充作开关来使用,在降低开关器件导通电压的同时简化了开关电路,缩小了电路的尺寸,并降低了电路的功耗。基于国内某工艺线的40 V互补双极型工艺,设计并制作了带正/负两路输出的开关电容电荷泵电压转换器芯片电路。流片测试结果表明：当电源电压为4 V（负载电流为0 mA、+10 mA）、5 V（负载电流为±10 mA）、9 V（负载电流为+10 mA）、10 V（负载电流为-10 mA）以及11 V（空载）时,输出电压均满足设计指标。     

一种用于PCRAM的嵌入式片内电容电荷泵

针对相变存储器小片内电容和低功耗的应用要求,在分析传统升压式电容电荷泵局限性的基础上,提出了一种应用于相变存储单元的嵌入式片内电容电荷泵。该电容电荷泵无需电感器件,存储单元不会受到高电磁干扰,采用了特殊的互补型电荷泵升压方法,具有电源效率高、瞬态响应速度快、面积小、电容可片内集成等优点。在SMIC 40 nm标准CMOS工艺条件下,对设计的嵌入式片内电容电荷泵进行仿真。结果表明,负载电流变化为250 mA/μs时,输出瞬态响应时间为374.2 ns,电源转换效率可达81.65%,静态电流为7.22 μA,输出能力为4 V/2.5 mA。     

用于TFT-LCD液晶显示的可调电荷泵设计

为了满足TFT-LCD液晶显示的驱动要求,设计了一种通过控制饱和区MOS管的导通电阻来调节输出电压的可调电荷泵。与传统的电荷泵相比,该电荷泵通过负反馈系统进行控制,具有输出可调、最少外围器件、低纹波、易于集成等优点。采用此可调电荷泵电路的芯片已在UMC0.6μm-BCD工艺线投片,测试结果表明,该可调电荷泵电路工作良好,独特的稳压方式使得电荷泵输出纹波降至最低,并且电荷泵的电容尺寸小,从而减小了整个系统的PCB面积,可调电荷泵正电压输出范围为10～30V,负电压输出范围为-5～-30V,负载电流为50mA时,输出纹波为27mV,可调电荷泵的整体效率可达80%。     

采用有限状态机控制的升降压双通路高效率电荷泵

针对诸如系统芯片中模拟和数字模块需工作在不同电源电压下的要求,提出一种可同时提供双路输出且具有多种增益模式的电荷泵,它仅利用一组开关电容阵列,根据输入电压与负载电流的变化自动为双通路选择合适的增益对,从而在提供稳定的输出电压同时使电荷泵具有较高的转换效率。专门引入增益跳变技术,改善了增益过渡的平滑性,进一步提高了转换效率。整个调制过程采用数字状态机控制,电路结构简单,响应速度快。芯片采用TSMC 0.35μm混合信号CMOS工艺设计并制造,仿真与测试结果显示设计目标均已实现,能够同时提供稳定的1.8 V和5.0 V的双路输出,动态响应迅速,转换效率比传统多增益模式电荷泵提高了10%以上。     

用于相变存储器的自适应1.5X/2X/3X高效电荷泵

针对相变存储器中编程驱动电路的电源效率问题,设计了一种1.5X/2X/3X自适应高效电荷泵,电路采用跳周期模式稳定输出电压.在中芯国际0.18 μm标准CMOS工艺模型下,对电路进行了仿真.结果表明,在输入电压为2.2～4.8 V时,输出5V电压,最大负载电流为10mA,电源效率最高可达94％.     

双模式高集成负电荷泵电路设计

提出了一种新颖的双模式高集成开关电容电荷泵。该电荷泵集成高频振荡器、电平移位、逻辑驱动以及4个功率MOSFET开关。与传统电荷泵相比,该电路可以工作在单电源以及双电源两种模式。单电源模式下,输出电压为-VCC;双电源模式下,输出电压为-3×VCC。电路采用0.35μm BCD工艺实现。测试结果表明:室温时,单电源模式和双电源模式下电荷泵输出电流分别为36 mA和80 mA时输出电压分别为-3.07 V和-12.10 V。在-55℃到125℃温度范围内,单电源模式和双电源模式下电荷泵输出电流分别为24 mA和50 mA时输出电压分别低于-3.06 V和-12.35 V。该电荷泵在两种模式下工作特性良好,已应用于相关工程项目。     

一种用于H桥功率驱动电路的电荷泵设计

提出了一种可驱动H桥功率电路的电荷泵.为了简化电路设计和确保电路稳定性,本电荷泵采用两倍压电荷泵电路拓扑结构,通过加入两路反馈控制电路来提高电荷泵充电电流和输出电压值的控制精度以及电源转换效率.设计采用0.35μm BCD工艺,通过Cadence Spectre仿真器表明,在负载电流为5mA条件下,电荷泵正常工作时输出电压范围广(10~40V),电源转换效率最高达到91%,输出电压建立所需时间为579μs.样片实测结果显示,在不同输入电压条件下,输出电压纹波控制在385mV以下.     

单片集成直流-直流转换器的效率提高方法

采用SMIC 0.13μm CMOS工艺,设计实现了开关频率达到250 MHz,单片集成的降压型电源转换器。为了提高电源转换效率,该转换器中的片上电感采用非对称性设计方法,提高了电感的品质因数。采用了高密度片上滤波电容来稳定输出电压,同时对单位电容尺寸的优化设计减小了电容的等效串联电阻以及输出电压纹波。测试结果表明,芯片输入电压为3.3 V,当输出2.5 V电压时,峰值效率达到了80%,最大输出电流达到270 mA;当输出1.8 V电压时,峰值效率达到了70%,最大输出电流达到400 mA。     

基于低压CMOS工艺的新型负电压型电荷泵电路

采用UMC 0.18 μm 1.8 V/3.3 V CMOS工艺设计并流片验证了一个应用于生医刺激器的新型负电压型电荷泵电路.介绍了几种典型的负电压型电荷泵电路,比较其优缺点,在此基础上设计了一个新型4级交叉耦合型负电压电荷泵.和现有的结构相比,该电路在启动过程和工作过程中都不存在过压问题,器件任意两端口之间的电压均小于电源电压VDD,同时降低了MOS器件衬底效应、反向漏电流对电荷泵效率的影响.电荷泵的电容采用MIM电容,升压电容为50 pF,输出电容为100 pF.芯片面积为2.3 mm×1.3 mm,测试结果表明负电压型电荷泵电路输出电压为-10.3 V,系统最高效率为56％.当输出电流为3.5 mA时,输出电容为100 pF时,纹波电压为150 mV.     

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.