ASON系统中可调谐半导体激光器的保护措施

针对智能光网络（As0N）通信系统中,当结温过高或电流过大的情况下不能使光源正常工作的问题,研究其基于半导体激光器多个工作环节的保护措施,并设计了慢启动保护、过流保护、温度保护、反向冲击电流保护、负反馈控制保护等电路,通过实验验证,这些电路能较好地对激光器进行保护。     

LDO中过温保护电路的设计

LDO是一个微型的片上系统,他包括调整管、采样网络、精密基准源、差分放大器、过流保护、过温保护等电路。分析了LDO中过温保护电路的设计,主要介绍了LDO中双极型过温保护电路和CMOS过温保护电路。由于双极器件开发早、工艺相对成熟、稳定,而且用双极工艺可以制造出速度高、驱动能力强、模拟精度高的器件,适用于高精度的模拟集成电路。因此,双极型集成稳压器应用广泛,其设计技术和制造工艺比较成熟和完善。但双极型过温保护电路本身存在热振荡的问题。给出一种新型的CMOS过温保护电路,他具有温度迟滞功能,有效地避免了芯片出现热振荡。     

一种具有过温与过流保护功能的LDO

为了防止功率管的功耗过大导致芯片受损,采用SMIC 0.18 μm CMOS工艺,设计了一种具有过温与过流保护功能的低压差线性稳压器。仿真结果表明,LDO电路具有良好的线性调整率和负载调整率,过温、过流保护电路能够实现对电路的保护。在过热、过流或负载短路的情况下,降低系统的功耗,且当故障排除后,可自动恢复工作。在2～3.6 V的输入电压范围内,电路的稳定输出电压为1.8 V,电源调整率不超过0.194‰,负载调整率不超过1.1‰。     

智能化电源模块

智能化电源模块英国Ｐｏｗｅｒｅｘ公司研制出的智能化电源模块最近投人大批量生产。此６００人６００Ｖ模块含有专门设计的、与ＩＧＢＴ特性匹配的集成电路。此系列产品具有四种保护性能：门驱动器过压断电保护，负载过电流保护，负载短路保护和过温保护。除此之外，还提...     

一种具有新型过温保护功能的LED恒流驱动电路

设计了一种具有滞回和过温缓冲保护功能的发光二极管(LED)恒流驱动电路。该电路由恒流驱动模块、滞回和过温关断模块、延时复位模块、滞回和过温缓冲模块组成;实现了电路的双温度滞回和过温缓冲保护功能,可对缓冲阶段所处的时域区间和温度区间进行调节。电路在过温缓冲跳变点和过温关断点附近分别有5 ℃和29 ℃的温度滞回区间,避免了电路发生热振荡,增大了电路正常工作区的范围,可保证电路高效稳定地运行。     

一种带过温过流过压保护的LDO设计

本文设计了一种带过温、过流和过压保护的低压差线性调整器,并采用增加零点方式进行补偿.电路设计采用2μm Bipolar工艺,用Hspice进行仿真验证.仿真结果表明,过温保护电路可以实现对电路的保护.当温度高于140℃时,过温保护电路将调整管关断,温度下降到105℃时,LDO恢复正常工作.最大输出电流为5A,超过最大输出电流时,过流保护电路将调整管关断.负载调整率不超过1％;电源调整率不超过0.1％..     

一种高精度过温保护电路的设计

基于UMC 0.25um BCD工艺,设计了一款高精度过温保护电路。通过基准电路中三极管的基极-发射极电压的负温度特性实现温度检测,调节电阻的比值产生迟滞温度量,避免了电路热振荡现象。经过HSPICE仿真验证,电路在温度130℃时,过温保护信号发生翻转,关断芯片,待温度降低到99℃时再次开启,具有31℃迟滞量。在电源电压变化时,过温保护电路的过温阈值和迟滞温度量偏差最大仅为0.24℃。     

一种采用双极工艺设计的过温保护电路

在设计开关电源的时候通常会加入过温保护电路,一旦开关电源内部的温度超过其允许的最高温度时,将停止内部电路的供电,为整个开关电源提供自身的保护,同时也保护了开关电源所供电的整机电路免遭破坏.文章提出了一种基于2μm双极工艺设计的过温保护电路,并通过Cadence Spectre仿真工具对电路的工作状态进行仿真.结果表明该...     

0.13μm CMOS高精度过温保护电路的设计

采用0.13 μm CMOS工艺,设计了一款过温保护电路.芯片内部温度超过109℃时,产生过温保护信号,电路停止工作,从而起到保护作用.为了防止产生热振荡,采用滞回方式.设计实现了在109℃时关断,78℃时再次开启,有31℃滞迟.仿真结果显示,在电源电压波动或工艺参数变化时,过温保护电路的热关断及迟滞阈值点漂移最大误差仅为2℃,稳定性好.     

XD3301过温保护模块的设计

主要介绍了降压型(Buck)DC/DC专用集成电路XD3301的基本功能和特点,并给XD3301设计了一种CMOS工艺的高精度过温保护电路,通过芯片结温和三极管的阈值进行比较,当芯片结温高于三极管的阈值时,关断开关管;而当芯片结温低于三极管的阈值时,打开开关管,芯片正常工作。给出了过温保护模块具体的电路设计原理、计算方法,并用HSpice软件对结果进行了仿真验证。     

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.