一种大动态光度测量对数放大器的设计

介绍了一种光电流对数压缩I／V转换电路的设计方法。该电路通过对数转换把光电二极管的宽动态范围的电流输入转换为低动态范围的电压输出,同时采用温度传感补偿电路来消除温度对对数转换电路的影响。     

具有固定电压的VLDO

500mA VLDO（非常低压差稳压器）LT3021的输入电压为1．4～10V，输出电压为1．2V、1．5V和1．8V，在工作电流达500mA时，仍保持160mV的压降，静态电流为120μA，停机时电流低于3μA。用3．3μF的低ESR陶瓷输出电容器优化了稳定性和瞬态响应，其他特点包括0．05％的电压调节和0．2％的负载调节，内部保护电路包括电池反向保护、限流以及具迟滞和反向电流保护的热限制。     

一种高精度能隙基准电压电路

在分析了几种基准电压源的基础上 ,设计并实现了一种高精度用于高速串行通信接口的 CMOS能隙基准电压电路。电路采用了两级高增益运放的优化结构 ,基于 TSMC公司的 CMOS 0 .2 5μm混合信号模型的仿真结果表明电路输出电压在 -5 0～ 70°C的温度内波动范围为 0 .0 5 7%。芯片流片测试结果发现基准电压电路在输入电压为 2 .5 V的条件下 ,工作在 -5 0～ 70°C的温度范围内 ,输出电压变化范围为 1 .2 3 3 7～ 1 .2 3 5 6V,输出电压变化率为 0 .1 5 4% ,与仿真结果之间的平均偏差为 0 .0 1 6%。能隙基准电压电路的版图面积为 1 5 8μm× 1 64μm。     

一种低温度系数曲率补偿带隙基准电路

设计了一种输出电压为0.72 V、带曲率补偿的带隙基准电路,该电路适用于收发器等数模混合电路。基于SMIC 0.18μm CMOS工艺,对电路进行了仿真和测试。结果表明,电路工作在1.5 V电源电压下时消耗100μA的电流,在1.3~1.8 V电压下以及-40℃~125℃温度范围内,可获得1.12×10-5V/℃的温度系数,电源抑制比为84 dB。     

1200 V功率MOS栅驱动集成电路的设计

文章在国内首次设计并研制出1200V功率MOS栅驱劝集成电路。该电路最高偏置电压(Voffset(max))为1200V，最大输出峰值电流为1A，最高工作频率100kHz，温度范围-55～125℃，可同时驱劝系统中用于三相图腾柱式输出的高低端功率器件，是SPIC的一种典型电路。     

带2阶温度补偿的多输出带隙基准电压源

基于传统带隙基准的原理,通过优化电路结构,消除双极晶体管基极．发射极电压中的非线性项,设计了一种带2阶补偿的多输出带隙基准电压源。整个电路采用CSMC0．5μmCMOS工艺模型进行仿真。Spectre仿真结果表明,在-55～125℃的温度范围内,带隙基准电压源的温度系数为3．1ppm／℃,在5V电源电压下,输出基准电压为1．2994V;带隙基准电压源的电源抑制比在低频时为84．5dB;在5v电源电压下,可以同时输出0—5V多个基准电压。     

可选择增益的模拟温度传感器

温度传感器LM94021及LM94022可提供4个不同增益让用户选择，分别是-5．5mV／℃、-8．2mV／℃、-10．9mV／℃及-13．6mV／℃，可监控-50～150℃范围内的温度。供电电压为1．5～5．5V，输出电压与感测的温度成反比，静态电流分别为9μA和5．4μA。     

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;     

一种新型的电流模式曲率补偿带隙基准源

提出了一种新型的低压带隙基准源,与传统的带隙基准不同,该电路引入了第三个电流,以消除双极型晶体管射基电压的温度非线性项,从而实现曲率补偿。采用0．18μmCMOS工艺进行设计验证,HSpice仿真结果表明,室温下的输出电压为623mV,-55～＋125℃范围内的温度系数为4．2ppm／℃,1．0～2．1V之间的电源调整率为0．9mV／V。     

为快速ADC提供电压箝位与DC偏置模拟电路

许多快速ADC都推荐0.6V-2.6V输入电压范围,如美国国家半导体公司的ADC1175（参考文献1）。但在某些应用中,必须要转换一个对称的模拟输入信号。本设计实例中的电路将一个-0．2V－＋0．2V范围的对称输入电压转换到推荐的0．6V－2．6V范围（图1）。该电路亦能防止输出电压低于-0.3V,以防止损坏ADC。     

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.     

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.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

中国建立EB级存储实验室,致力云计算应用(英文)

正With the support of 863 programs,Sugon Information Industry Co.,Ltd.,set up a dawning EB-class storage laboratory to address massive data storage requirements and largescale cloud computing demonstration applications.The Dawning EB-class cloud storage system adopts advanced fault-tolerant architecture,efficient data fault-tolerant algorithms with user authentication and data encryption policies to deal with the"lost""wrong"and"stolen"problems of data for ensuring the reliability and safety of the EB-class storage system in the public network application environments.The Dawning EB-class Storage Laboratory taking advan-