0.6V电源电压的CMOS基准源设计及稳定性分析

在SMIC 0.18μm CMOS工艺下实现了一种工作在0.6～1.5V下的基准源.分别采用环路增益法和返回比法对其中的自偏置放大器和核心电路的环路特性进行了分析.芯片输出的基准电压为0.4V,工作电流为4.8μA,在-40～120℃范围内温度系数小于80ppm/℃,面积(不包括PAD)为0.045mm2.     

一种高性能的亚阈值基准电压源设计

本文给出了一种基于亚阈值MOS特性的基准电压源.通过使用线性区工作的MOS管代替传统电阻来消除掉迁移率和电流的温度影响,拓宽了温度范围,改善了性能.采用0.5μmCMOS工艺进行仿真.结果表明电路能在2.5～8V范围内工作,线性调整率为0.3mV/V.在3.3V工作电压下,输出基准在-55℃到150℃温度范围内温度系数为7.3ppm/℃,静态功耗为13.8μW,1kHz下电源抑制比为-53dB.该基准电压源的设计能满足宽温度范围、低温漂、低功耗和高电源抑制比的要求.     

一种新颖的高电源抑制比亚阈值MOSFET电流基准源

基于亚阈值MOSFET,提出了一种新颖的高电源抑制比(PSRR)电流基准源。基准电路充分利用工作在亚阈值区MOSFET的I-V跨导特性和改进的具有高负反馈环路增益预电压调制,为电流基准核电路提供电源。电路设计采用SMIC 0.18μm标准CMOS数字工艺技术。在1.5 V电源电压下,电路输出1.701μA的稳定电流,在-40℃到150℃温度范围内,具有非常低的温度系数(2.5×10-4μA/℃);并且,在宽泛的频率范围内,具有很好的电源噪声抑制能力。电源抑制比在dc频率为-126 dB,在高于1 MHz频率范围内,仍能保持-92 dB。基准电路在高于1.2V电源电压下可以稳定工作,并具有很好的CMOS工艺兼容性。     

1V电源的CMOS能隙电压基准源

采用SMIC 0.35μm CMOS工艺实现了一种可以工作在1V电源电压下的CMOS能隙基准源.测试表明,该电路可以工作在1～2.5V电源电压下,输出的基准电压可以稳定在约0.446V.在从室温到100℃的范围内,温度系数不超过3.6×10-5/K.     

一种应用于TCXO的带隙基准源设计

采用CSMC 0.35μm混合工艺设计了一种应用于温度补偿晶体振荡器(TCXO)的低功耗带隙基准电压源和电压转换电路.可提供可调的多种参考电压,同时设计了启动与逻辑控制电路,确保基准电路能正常工作并降低功耗.Cadence Spectre仿真结果显示,采用3 V的电源电压,在-40℃～85℃范围内温度系数为14.5 ppm/℃,电源电压大干2.2 V即可正常启动,在正常工作情况下,基准功耗小于10μW,低频电源抑制比为83.2 dB.     

一种低温漂低功耗的带隙基准源的设计

设计一种低温漂低功耗的带隙基准结构,在传统带隙基准核心电路结构上增加一对PNP管,两个双极型晶体管叠加的结构减小了运放的失调电压对输出电压的影响,降低了基准电压的温度失调系数.电路设计与仿真基于CSMC0.5μm CMOS工艺,经流片,测得室温下带隙基准输出电压为1.326 65 V,在-40～+85℃范围内的温度系数为2.563 ppm/℃;在3.3 V电源电压下,整个电路的功耗仅为2.81μW;在2～4 V之间的电源调整率为206.95 ppm.     

一种宽电源电压的高精度带隙基准电路的设计

设计了一种宽电源电压的高精度带隙基准电路.在综合考虑精度、电源抑制比(PSRR)、宽电源电压要求和功耗等因素的基础上,采用了一种由基准电压偏置的,增益和电源抑制比大小相近的运算放大器解决方案.设计采用CSMC 0.5μm CMOS工艺,电源为3.3V. Cadence Spectre 仿真表明,当温度在 -40 ℃～125 ℃,电源电压在2.56V～8V时,输出基准电压平均值为1.290V,变化0.793mV,有效温度系数为3.72ppm/ ℃;室温下,在低频时具有-97dB的PSRR,在100kHz时为-69dB,功耗为180μW.     

一种改进的高精度BiCMOS带隙基准源的设计

在对传统带隙基准源的误差进行分析的基础上,介绍了一种改进的带隙核结构,该结构能有效抑制电流失配对带隙基准电压带来的影响。根据该结构设计了一种高精度BiCMOS带隙基准源。HSPICE仿真结果表明,该带隙基准源产生1.22V基准电压,在-25℃～ 125℃温度范围内具有3.1×10-6/℃的温度系数。在25℃时和3.6V标准电源电压条件下,电源抑制比达76dB,静态工作电流为6.9μA,在2.7V～6V的电源电压范围内线性调整率为0.142mV/V。     

一种基于BCD工艺的新型5V基准电路设计

设计了一种结构简单的新型基准电路,通过对带隙基准的倍乘,无需电压转换电路,输出5V基准电压可直接用于芯片次级电源.电路设计中,运用驱动电路提高基准电压的驱动能力,通过温度补偿、电路隔离技术和反馈环路,提高基准电压的温度特性、电压抑制比和稳定性.全电路基于0.35μm BCD工艺,并通过Hspice仿真.结果表明,基准电压输出为5V,驱动能力20mA,温度系数5.1ppm/℃;室温下,电源抑制比63dB@100kHz.     

低温漂高电源抑制的CMOS片上电流源

设计了一种用于驱动电路和模数转换器的片上电流源,该结构利用带隙基准的方法产生了一个与温度无关的参考电平,同时为了满足高电源抑制的要求,电流源中采用了运算放大器的负反馈环路来抑制电源到输出的增益,从而使输出电平与电源电压无关,然后通过电阻把电压转化为电流.该电路在0.35,μm、3.3 V的工艺下实现,芯片面积为0.03 mm2.仿真和测试结果表明,该电流源的温度系数为8.7×10-6/℃,在2.6～4 V的电源电压下均能正常工作,达到了系统要求.     

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-