新时代数字音乐的效果提升器Cambridge Audio DacMagic升频DAC

<正>基本规格输入:2×数字输入(每个可选择同轴或光纤)、音频输出:1×镀金RCA唱机输出、1×XLR均衡输出、1×同轴数字输出、1×光纤输出、D/A转换器:双Wolfson WM8740 24bit DAC、模拟滤波器:2极差分Bessel双虚拟接地均衡、频率响应:20Hz到KHz(±0.1dB)、信噪比:112 dBr、功耗:18W、体积:W52×H215×D191、重量:2kg     

双输出低压差线性稳压器MAX8530

MAX8530是MAXIM公司生产的器件,它是一种双输出、低功耗、低压差线性稳压器。该器件主要特点:输出1(OUT1)保证输出200mA;输出2(OUT2)保证输出150mA;OUT1及OUT2有多种电压输出(详见表1),用户也可根据电路需要确定要求的OUT1及OUT2的电压(在1.5～3.3V范围之内)向工厂订货;两个电源是相互独立的并且都是低压差,在100mA输出时其压差典型值为100mV;工作电压范围2.5～6.5V;当OUT1输出电压低于87%正常输出电压时,RESET端输出100ms的复位信号(低电平有效);静态电流小,典型值130μA;有省电关闭控制,关闭状态时耗电小于1μA;内部有输…     

应用专利技术的CATV放大器和光接收机

本文介绍一种实用专利技术的CATV放大器和光接收机。实用新型专利《用开关控制输出状态的放大器》(专利号:ZL98249453×)中的关键是在放大器电路中设计了由2分配器P、1分支器Z和1只2位3刀开关K_1组成的输出状态控制电路,拨动开关K_1就可方便的控制放大器的两个输出端工作在分配输出状态或分支输出状态。图1、图2分别     

LT1761系列LDC

LT1761系列低压差线性稳压器是凌力尔特公司的产品,是一种微功耗、低噪声、输出100mA的低压差线性稳压器（LDO）系列。该系列主要特点：噪声低,在10Hz～100kHz时为20μVrms;静态电流低：20μA;输入电压范围宽,从1．8V-20V;输出电流可达100mA;有关闭电源控制,在关闭状态时耗电小于0．1uA;输入、输出电压差低,在输出100mA时为300mV;有固定电压输出（1．2V、1．5V、1．8V、2V、2．5V、2．8V、3V、3．3V、5V）及输出可调（1．22V到20V）的品种供用户选择;     

高手接招

答:(今年第10期)上海徐瑞国先生关于运放集成块如何由双电源供电改为单电源供电的问题、采用双电源为运放块供电,其输出电位比电源电压(正负)的绝对值低1V左右,即: 输出正电位时,输出=正电源-1V 输出负电位时,输出=负电源 1V 改为单电源后,输出的高电位同上:但输出低电位即0电位时,并不为0V,而是     

超低功率14位和12位ADC

LTC2145在采用单1．8V电源时每Msps的功率消耗低干1mW。LTC2145系列包括两通道同时采样、并行输出ADC,提供了全速CMOS、双倍数据速率（DDR）CMOS或DDRLVDS数字输出选项,以及可编程数字输出定时、     

降压式电荷泵电路MAX1730

MAX1730是一种输出稳压的降压式电荷泵电路，它输出固定的1．8V或1．9V，输出电流可达50mA。介绍其特性、结构、工作原理及应用电路。     

电流模式降压-升压型转换器

LTC3114-1可用多种电源提供高达1A连续输出电流,包括单节锂离子电池、24V／28V工业电源轨和40V汽车输入。LT C3114-1在2．2～40V输入和2．7～40V输出范围内提供稳定输出,输入可高于、低干或等于调节的输出电压,从而最大限度地提高了电源灵活性,就仅为降压型的解决方案而言,     

LTC3115-1：降压-升压型转换器

凌力尔特公司推出同步降压-升压型转换器LTC3115—1．该器件可使用从单节锂离子电池、24V／28V工业电源轨到40V汽车输入的多种电源,提供高达2A的连续输出电流。LTC3115-1具2．7V-40V的输入和输出范围,在输入高于、低于或等于输出时,可提供稳定的输出。     

2001年全国大学生电子设计竞赛一等奖——高效率音频功率放大器

<正> 本设计主要由功率放大器、信号变换电路、输出功率显示电路和保护电路组成。功率放大器部分采用D类功率放大器确保高效率,在5V供电情况下输出功率大于1W,且输出波形无明显失真,低频输出噪声电压很低(输出频率为20kHz以下时,低频噪声电压约1mV);信号变换部分采用差分放大电路,将双端输出信号变为1:1的单端输出信号;输出功率显示部分用乘法器电路及带A/D转换的电压表头显示功率值,电路简单合理;保护电路部分采用电流互感器监控,实现输出短路保护。 题目分析及设计方案论证与比较 根据题目要求,整个系统由D类功率放大器、信号转换电路及功率测量显示装置组成。系统组成如图1所示。     

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.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

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.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.