0．18μm直接式数字频率合成器全定制版图设计

文章采用0．18μm混合信号1P6M1．8W3．3VCMOS工艺,介绍了一种高速直接式数字频率合成器的全定制版图设计。该芯片为数模混合信号IC,电路内部时钟频率达到1GHz。版图设计过程中采用了集成无源金属-绝缘体-金属（MIM）结构电容及深N阱技术,使用了合适的版图布局和电源、地线、时钟网络拓扑结构,最后还对芯片各模块作了版图优化设计。芯片测试结果表明芯片功能全部实现、性能良好,版图设计较好地实现了电路功能。     

基于标准CMOS工艺的一款宽带限幅放大器芯片设计

采用SMIC 0．35μm CMOS混合信号工艺来设计开发一款适用于SDH STM-16的光接收机前端限幅放大器芯片。该限幅放大器的设计采用了电容中和技术来实现带宽的扩展,可满足2．5Gbps速率要求,芯片电路拥有信号丢失检测和自动静噪功能。芯片版图的参数提取仿真表明：芯片最小输入动态范围可达2mV,50Ω负载上的双端输出摆幅约为1400mVpp在3．3V供电下静态功耗仅为66mW,动态功耗为105mW,有实际推广价值。     

一种新颖的可编程电压监测芯片

提出了一种新颖的可编程电压监测芯片设计。该芯片无需任何外部元件,仅对3个编程管脚采取不同的连接方式,即可实现36种不同的编程状态,一颗芯片可以覆盖1.5V到5.0V的电压范围。同时,特殊时序的采样保持电路和数字限流模块的设计使其具有极低的静态功耗。该芯片基于0.5μm的混合信号工艺实现,芯片面积为0.24mm2,仅消耗3μA静态电流。     

一种1024级灰度大电容负载的LCD驱动芯片设计

设计了一种基于动态扫描原理的液晶显示(LCD)驱动芯片。该芯片为高压CMOS数模混合集成电路并支持输出频率可选功能。芯片输入数据频率为13.5MHz,输出1 024级256列模拟电压信号直接驱动LCD,输出电压幅度可达12V以上。负载为200pF时,最大摆幅上升/下降时间小于5μs。芯片采用新加坡特许半导体(Chartered)0.35μm、18V高压工艺设计,并进行了仔细的版图设计以减小匹配误差,仿真结果显示电路性能完全满足设计指标要求。     

汽车电压调节器集成电路芯片版图设计

介绍了基于4μm双极型对通隔离工艺的汽车电压调节器功率集成电路芯片的版图设计。版图设计的主要出发点是高精度、大调整电流和高可靠性三方面。版图中各模块采用了热对称设计和等温线设计,关键元件的匹配采用了中心对称设计,大功率调整管采用了宽发射极窄接触条和圣诞树型结构相结合的方案。芯片测试结果表明,电压调节器的调节精度为14.2±0.15V,最大调节电流为5A,较好地实现了预定电路功能。芯片成品率达80%。     

一种12位80 MS/s CMOS流水线ADC设计

介绍了一种12 bit 80 MS/s流水线ADC的设计,用于基带信号处理,其中第一级采用了2.5 bit级电路,采样保持级采用了自举开关提高线性,后级电路采用了缩减技术,节省了芯片面积.采用了折叠增益自举运放,优化了运放的建立速度,节省了功耗.芯片采用HJTC0.18μm标准CMOS工艺,1.8 V电压供电,版图面积2.3 mm × 1.4 mm.版图后仿真表明,ADC在8 MHz正弦信号1 V峰值输入下,可以达到11.10 bit有效精度,SFDR达到80.16 dB,整个芯片的功耗为155 mW.     

一种智能化漏电保护芯片的设计

提出了一种智能化漏电保护芯片。电路基于0.6μm CMOS工艺、采用数模混合信号设计,并用全定制的方法实现。与现有模拟漏电保护芯片相比,该芯片具有较高的智能化:对输入信号是否有效进行辨识,以排除干扰,减少误动作;采用数字延时代替现有的RC延时方式,大大提高了控制精度及三级匹配;三级保护的不同应用环境的可编程性;实现智能化开关控制;具有报警功能,保障安全。由于芯片的大部分功能由数字电路实现,大大降低了功耗。通过采用全定制的方法,优化电路和版图设计,减少了芯片面积,降低了成本。     

一种高线性度100 kHz带宽∑△调制器

设计了一个100 kHz信号带宽、80 dB SNDR、3.3 V电源电压的单环三阶∑△调制器.电路采用AB类运放,可在较低静态功耗下实现较高的压摆率.电路采用UMC 0.18μm CMOS工艺制作,版图面积为1.7 mm×1.3 mm.芯片测试结果显示:在12 MHz时钟频率、60倍过采样下,调制器可达到100 kHz信号带宽,75.7 dB SNDR和98 dB SFDR.     

可编程频率合成芯片SY89429V在等效采样中的应用

简要介绍了等效采样的原理,以及可编程频率合成芯片SY89429V的主要功能和特点,并给出SY89429V在一个等效采样系统中的具体应用.该采样系统还包括微控制器、高速ADC、可编程逻辑器件和高速RAM,实现了对1～80 MHz周期信号波形的复现.     

新型电容式MEMS加速度计数字接口电路设计

MEMS加速度计接口电路主要采用传统sigma-delta架构实现,但这种方式中的电路失调电压很容易产生积分饱和现象．为解决这个问题,本文设计了一种可以用于钻井、石油勘探等微弱信号检测的新型数字电容接口电路．该设计在电容式MEMS加速度传感器基础上,采用FPGA实现数字三阶环路滤波器,构成5阶sigma-delta系统．采用数字环路滤波器降低了ASIC模拟电路版图设计与芯片测试难度,利于快速优化环路滤波器设计参数,改善系统稳定性和优化系统噪声性能．前置放大器采用一种相对简单的相关双采样技术,能够有效减小前置放大器的失调电压．根据MEMS加速度计前置放大器输出信号符合正态分布的特点,设计了带有一定预测功能的8-bit瞬时浮点ADC,实现模拟与数字环路滤波器互联．在200Hz带宽内,该接口电路系统噪声基底达到53．09ng／rt（Hz）,满足系统噪声设计要求．前置放大器与ADC采用XFAB XH018混合信号CMOS工艺流片,开环测试表明,前置放大器的灵敏度和噪声分别为0．69V／pF和3．20μV／rt（Hz）．     

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.     

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.     

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.     

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.     

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.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.