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%。     

一种低电压、高增益电荷泵

电荷泵在低压电路中扮演着重要的角色。作为片上电荷泵,其面临的主要问题是:电压增益、电压纹波和面积效率。该文提出了一种新型的电荷泵电路,它采用辅助电荷泵、电平转移电路结构来产生不同摆幅的时钟,该时钟被用来驱动开关管的栅极,以有效控制开关管的电导,提高电压增益。由于采用PMOS管作为开关管,传输过程中避免了阈值电压损失。仿真结果显示,与以往文献中提到的电荷泵结构相比,该电荷泵具有更高的电压增益,开启时间短,纹波小,在低压应用环境优势更为突出。     

一种具有输出限压功能的电荷泵的设计

在传统的电荷泵中,通常将更多的设计重点放在电荷泵的升压效率问题上。但是,在低电压工艺中,过高的电压会让MOS管处于被击穿的危险之中,同时,开关管的导通电阻随电源电压的变化很明显。针对上述问题,提出了一种具有输出限压功能的电荷泵。采用0.5 μm UMC工艺,利用Cadence和Hspice软件进行电路设计与仿真。结果表明,当电源电压在2.7~5.5 V范围内变化时,电荷泵的输出电压可控制在一定范围内,并且开关管的导通电阻变化很小。     

具有安全保护的高性能电荷泵

设计了一种能有效控制电流过冲与输出短路电流的高性能电荷泵稳压器,它通过改变误差放大器输出来控制电荷泵开关管电流,使得电荷泵在启动阶段具有输出短路控制,在正常工作时能够有效抑制电流过冲.理论分析和仿真结果表明,采用此结构的电荷泵稳压器输出短路电流最大值为110 mA,远小于电荷泵正常工作时开关充电电流500mA.     

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.     

一种高效率开关频率自适应电荷泵

本文提出了一种新型开关频率自适应电荷泵,它通过自动调节电荷泵开关频率,降低了芯片静态电流.与传统的固定开关频率线性控制电荷泵相比,开关频率自适应电荷泵具有更低的静态电流,更高的转换效率,稍高的输出纹波.特别是在电荷泵工作于轻负载时,其转换效率提升非常显著.理论分析和仿真结果表明在轻负载情况下,开关频率自适应电荷泵的效率比固定开关频率线性控制电荷泵效率提高了10%～40%.     

用于相变存储器的高效开关电容电荷泵

提出一种应用于相变存储器芯片的新型开关电容电荷泵。对于16 位的相变存储器芯片,系统擦写时间大于100 ns,电荷泵的驱动能力至少为60 mA。相比于传统开关电容电荷泵,该电荷泵根据负载电流大小自动生成一个使能信号,该信号通过控制升压模块功率管的开启与关断来调节输出电压,最终将输出电压控制在一个允许的范围内波动。采用40 nm CMOS工艺对电荷泵进行设计和仿真,结果表明在5 mA负载时,电源效率为87%,输出纹波为2.84 mV;负载电流从0 mA变化到60 mA时,电源效率皆高于82%;负载电流变化在300 mA/μs时,输出瞬态响应时间为1.63 μs,满足相变存储器芯片的使用要求。     

一种低压改进型MOS电荷泵电路的设计

针对使用标准CMOS技术实现的传统电荷泵输出电压较低的不足,文中提出将基本的电荷转移开关进行改进的MOS电荷泵,在泵送增益增加电路的基础上,通过在泵的输出级增加第3个控制信号来提高电荷泵的电压增益,以得到更高的输出电压,将其作为无线传感器的能量收集电路。仿真结果表明,该改进型电荷泵电路适合于低电压设备,并具有较高的泵送增益。其输出电压在同类电荷泵中最高,在1.5 V电源条件下,可高达8.5 V。     

一种采用齐纳管作为开关器件的Dickson电荷泵电路

文章提出了一种基于Dickson原理的电荷泵电路,采用齐纳管作为开关器件。该电路克服了采用MOS管作为开关器件的Dickson电路在多级级联时的转换效率急剧下降问题,并且可以利用齐纳管来稳定输出电压。Spice仿真结果显示,五级齐纳电荷泵可以轻松在3V电源电压下实现10V左右的稳定电压输出。该电路结构简单,与标准CMOS工艺兼容,具有较高的应用价值和经济价值。     

基于传输线的纳秒脉冲成形电路研究

提出了一种脉冲成形和脉冲展宽的方法，在基于理想开关的纳秒脉冲成形电路基础上，使用MOS管代替理想开关，保证MOS管工作在饱和区实现了脉冲成形，分析了MOS开关进入饱和区后在不改变传输线延迟时间的情况下，改变电源电压可以实现脉冲展宽，并通过实验验证了仿真获得的结果。     

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.