ISO/IEC JTC1/SC32数据管理与交换领域标准国际动态

2010年5月17～28日,LSO／IEC JTG1／SC32工作组会议及全体会议在中国昆明召开,来自中国、日本、韩国、美国、英国、加拿大、德国共7个国家的70位代表参加了本次会议,中国代表团由工业和信息化部电子工业标准化研究所、中国标准化研究院、武汉大学等单位的23名代表组成。国家标准化管理委员会作为ISO／IEC,JTC1中国国家委员会承办了本次会议。     

中兴通讯率先完成TD-LTE S1/X2接口一致性测试

2010年6月1日,中兴通讯与工业和信息化部完成了S1/X2接口一致性的正式测试,该项测试是工业和信息化部TD-LTE研究开发技术试验测试的重要组成部分。在该测试大规模启动前,中兴通讯作为系统厂家在仪表模拟环境下率先进行了测试工作,凭借其在TD—LTE领域的丰富经验,顺利通过S1／X2接口一致性测试全部条目,成为第一家完成该测试集的厂家。     

模拟/电源

真正色彩 PWM 调光的60V 降压型转换器 Linear推出60V、1MHz降压型DC／DC转换器LT3596,作为恒定电流LED驱动器以驱动多达30个LED。就48V输入而言,LT3596可驱动多达3串各含10个100mA串联LED的LED串,可提供超过90％的效率。LT3596的多通道能力使其非常适用于大型LED广告牌以及工业和医疗显示器。     

元件/连接器

泰科电子推TINMAN85欧姆连接器;以太网性能高达10Gigabit／工业7类连接器;Vishay新3mm红外发射器性能赶超5mm。     

ISO／IECJTC1／SC6数据通信领域新动向

2009年6月1-5日,ISO／IEC JTC1／S06全会在日本东京召开,参加此次会议的有11个国家以及来自ECMA international、ITU—T和IEEE LMSC等联络组织的代表。中国代表团团长为工业和信息化部电子工业标准化研究所徐冬梅。     

MCP6V01/2/3：自动调零运算放大器

Microchip推出MCP6V01／2／3（MCP6VOx）自动调零运算放大器。这款低功耗运算放大器配备独特的自校正架构,可实现超高精度,输入偏移电压仅为2pV。此外,新器件还具有高共模抑制、轨对轨输入／输出及低静态电流等特点,适用于工业及医疗等市场上以电池供电的便携式设备。     

22Mbit/s、155Mbit/sSDH光纤系统的开发

从１９８８年起，邮电部第五研究所开始ＳＤＨ系统的开发。最近该所又用３年时间，同中国邮电工业总公司合作开发了６２２Ｍｂｉｔ／ｓ和１５５Ｍｂｉｔ／ｓ两个速率级的全套设备（包括ＴＭ、ＡＤＭ、中继机）和ＦＰ１．０版的网元管理系统。本文将介绍开发的背景和产品开发的成果     

不同厂牌LS3/5A声音为何不同

总的来说,LS3／5A就是LS3／5A的声音LS3／SA设计于20世纪70年代初,当时正值古典音乐盛行,流行音乐初步萌生的时代,这个时期也是英国的传统音响工业发展最为鼎盛的阶段。     

基于ARM968核的125MHz MCU

LPC292x系列是适合工业网络、报警系统和电机控制应用的高速微控制器。该系列具有ARM968ES工业标准RISC核,运行在125MHz,提供高性能（1．1MIPS／MHz）及低功耗。其他特性包括全速USB2．0 Host／OTG／Device、双CAN接口和两个LIN主控器、16KBEEPROM、标准串行总线,加上一个成熟的PWM和两个3V、一个5VADC。     

I/f噪声源及MOS器件中的1/f噪声

1／f噪声,由于其反映了器件的质量、可靠性等参数,其研究越来越为人们所重视。本文首先较为系统地介绍了1／f噪声源两种较为成熟的理论：载流子数涨落和迁移率涨落模型,最后将研究MOS晶体管中1／f噪声的现象。在n管中,较为成功地用△N模型;而在PMOS晶体管中,△μ模型可较为成功地解释其1／f噪声特性。     

Performance improvement in tensile-strained In/sub 0.5/Al/sub 0.5/As/In/sub x/Ga/sub 1-x/As/In/sub 0.5/Al/sub 0.5/As metamorphic HEMT

This paper proposes a In/sub 0.5/Al/sub 0.5/As/In/sub x/Ga/sub 1-x/As/In/sub 0.5/Al/sub 0.5/As (x=0.3-0.5-0.3) metamorphic high-electron mobility transistor with tensile-strained channel. The tensile-strained channel structure exhibits significant improvements in dc and RF characteristics, including extrinsic transconductance, current driving capability, thermal stability, unity-gain cutoff frequency, maximum oscillation frequency, output power, power gain, and power added efficiency.     

Very low-noise Al/sub 0.3/Ga/sub 0.7/As/Ga/sub 0.65/In/sub 0.35/As/GaAs single quantum-well pseudomorphic HEMTs

AlGaAs/GaInAs/GaAs pseudomorphic HEMTs with an InAs mole fraction as high as 35% in the channel has been successfully fabricated. The device exhibits a maximum extrinsic transconductance of 700 mS/mm. At 18 GHz, a minimum noise figure of 0.55 dB with 15.0 dB associated gain was measured. At 60 GHz, a minimum noise figure as low as 1.6 dB with 7.6 dB associated gain was also obtained. This is the best noise performance yet reported for GaAs-based HEMTs.<>     

A 12 /spl times/ 12 In/sub 0.53/Ga/sub 0.47/As-In/sub 0.52/Al/sub 0.48/As avalanche photodiode array

We report a 12 /spl times/ 12 In/sub 0.53/Ga/sub 0.47/As-In/sub 0.52/Al/sub 0.48/As avalanche photodiode (APD) array. The mean breakdown voltage of the APD was 57.9 V and the standard deviation was less than 0.1 V. The mean dark current was /spl sim/2 and /spl sim/300 nA, and the standard deviation was /spl sim/0.19 and /spl sim/60 nA at unity gain (V/sub bias/ = 13.5 V) and at 90% of the breakdown voltage, respectively. External quantum efficiency was above 40% in the wavelength range from 1.0 to 1.6 /spl mu/m. It was /spl sim/57% and /spl sim/45% at 1.3 and 1.55 /spl mu/m, respectively. A bandwidth of 13 GHz was achieved at low gain.     

Al/sub 0.3/Ga/sub 0.7/As/In/sub x/Ga/sub 1-x/As (0/spl les/x/spl les/0.25) doped-channel field-effect transistors (DCFET's)

The properties of both lattice-matched and strained doped-channel field-effect transistors (DCFET's) have been investigated in AlGaAs/In/sub x/Ga/sub 1-x/As (0/spl les/x/spl les/0.25) heterostructures with various indium mole fractions. Through electrical characterization of grown layers in conjunction with the dc and microwave device characteristics, we observed that the introduction of a 150-/spl Aring/ thick strained In/sub 0.15/Ga/sub 0.85/As channel can enhance device performance, compared to the lattice-matched one. However, a degradation of device performance was observed for larger indium mole fractions, up to x=0.25, which is associated with strain relaxation in this highly strained channel. DCFET's also preserved a more reliable performance after biased-stress testings.<>     

Morphological and electrical characterization of SixCryCzBv thin films

Si_xCr_yC_zB_v thin films with several compositions have been studied for integration of high precision resistors in 0.8 μm BICMOS technology. These resistors, integrated in the back-end of line, have the advantage to provide high level of integration and attractive electrical behavior in temperature, for analog devices. The film morphology and the structure have been investigated through transmission electron microscopy analysis and have been then related to the electrical properties on the base of the percolation theory. According to this theory, and in agreement with experimental results, negative thermal coefficient of resistance (TCR) has been obtained for samples with low Cr content, corresponding to a crystalline volume fraction below the percolation threshold.Samples with higher Cr content exhibit, instead, a variation of the TCR as a function of film thickness: negative TCR values are obtained for thickness lower than 5 nm, corresponding to a crystalline volume fraction below the percolation threshold; positive TCR are obtained for larger thickness, indicating the establishment of a continuous conductive path between the Cr rich grains. This property seems to be determinant in order to assure the possibility to obtain thin film resistors almost independent on the temperature.     

Highly linear Al/sub 0.3/Ga/sub 0.7/N-Al/sub 0.05/Ga/sub 0.95/N-GaN composite-channel HEMTs

We report an Al/sub 0.3/Ga/sub 0.7/N-Al/sub 0.05/Ga/sub 0.95/N-GaN composite-channel HEMT with enhanced linearity. By engineering the channel region, i.e., inserting a 6-nm-thick AlGaN layer with 5% Al composition in the channel region, a composite-channel HEMT was demonstrated. Transconductance and cutoff frequencies of a 1 /spl times/100 /spl mu/m HEMT are kept near their peak values throughout the low- and high-current operating levels, a desirable feature for linear power amplifiers. The composite-channel HEMT exhibits a peak transconductance of 150 mS/mm, a peak current gain cutoff frequency (f/sub T/) of 12 GHz and a peak power gain cutoff frequency (f/sub max/) of 30 GHz. For devices grown on sapphire substrate, maximum power density of 3.38 W/mm, power-added efficiency of 45% are obtained at 2 GHz. The output third-order intercept point (OIP3) is 33.2 dBm from two-tone measurement at 2 GHz.     

Comparison between Pt/TiO2/Pt and Pt/TaOX/TaOY/Pt based bipolar resistive switching devices

Nonvolatile memories have emerged in recent years and have become a leading candidate towards replacing dynamic and static random-access memory devices. In this article, the performances of TiO₂ and TaO₂ nonvolatile memristive devices were compared and the factors that make TaO₂ memristive devices better than TiO₂ memristive devices were studied. TaO₂ memristive devices have shown better endurance performances (10⁸ times more switching cycles) and faster switching speed (5 times) than TiO₂ memristive devices. Electroforming of TaO₂ memristive devices requires~4.5 times less energy than TiO₂ memristive devices of a similar size. The retention period of TaO₂ memristive devices is expected to exceed 10 years with sufficient experimental evidence. In addition to comparing device performances, this article also explains the differences in physical device structure, switching mechanism, and resistance switching performances of TiO₂ and TaO₂ memristive devices. This article summarizes the reasons that give TaO₂ memristive devices the advantage over TiO₂ memristive devices, in terms of electroformation, switching speed, and endurance.     

Electrooptic ferroelectric Na/sub 0.5/K/sub 0.5/NbO/sub 3/ films

We report on waveguiding and electrooptic properties of epitaxial Na/sub 0.5/K/sub 0.5/NbO/sub 3/ films grown by radio-frequency magnetron sputtering on Al/sub 2/O/sub 3/(11_02) single crystal substrates. High optical waveguiding performance has been demonstrated in infrared and visible light. The in-plane electrooptic effect has been recorded in transmission using a transverse geometry. At dc fields, the effective linear electrooptic coefficient was determined to 28 pm/V, which is promising for modulator applications.