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if-else-end

  • 智能电表和智能电网手册

    Abstract: Investment in smart meters and smart grid end equipment continues to grow worldwide as countriestry to make their electric delivery systems more efficient. However, as critical as the electric deliveryinfrastructure is, it is normally not secured and thus subject to attack. This article describes the concept oflife-cycle security—the idea that embedded equipment in the smart grid must have security designed into theentire life of the product, even back to the contract manufacturer. We also talk about how life-cycle securityapplies to embedded equipment in the smart grid. Potential threats are discussed, as are potential solutionsto mitigate the risks posed by those threats.

    标签: 智能电表 智能电网

    上传时间: 2014-12-24

    上传用户:熊少锋

  • 电源供应器与数字电位器校准应用笔记

    Abstract: A resistive feedback network is often used to set the output voltage of a power supply. A mechanical potentiometer (pot)conveniently solves the problem of adjusting a power supply. For easier automatic calibration, a mechanical pot can be replaced witha digital pot. This application note presents a calibration solution that uses a digital pot, because digipots are smaller, do not movewith age or vibration, and can be recalibrated remotely. This proposed solution reduces the susceptibility of the system to thetolerance of the digital pot's end-to-end resistance, making the solution optimal fordesigners. This application note also explainssome of the equations required to calculate the resistor chain values and to use a digital pot in this way. A spreadsheet withstandard reisistor values is available for easy calculations.

    标签: 电源供应器 数字电位器 应用笔记 校准

    上传时间: 2013-10-31

    上传用户:caiguoqing

  • Altera FPGA的电源解决方案

    Abstract: Field-programmable gate arrays (FPGAs) are used in a wide variety of applications and end markets, including digital signalprocessing, medical imaging, and high-performance computing. This application note outlines the issues related to powering FPGAs.It also discusses Maxim's solutions for powering Altera® FPGAs.  

    标签: Altera FPGA 电源解决方案

    上传时间: 2013-11-02

    上传用户:zhaoman32

  • 使用5V电源的高分辨率视频解决方案

      Video cable driver amplifi er output stages traditionallyrequire a supply voltage of at least 6V in order to providethe required output swing. This requirement is usuallymet with 5V supplies by adding a boost regulator or asmall local negative rail, say via the popular LT®1983-3.Such additional circuitry is unnecessary in typical 1VP-Pvideo connections, such as HD component video, if thecable driver amplifi ers simply offer near rail-to-rail outputcapability when powered from 5V.

    标签: 5V电源 高分辨率 视频解决 方案

    上传时间: 2013-11-16

    上传用户:yanyangtian

  • DN464 高效率USB电源管理系统

      Automotive power systems are unforgiving electronicenvironments. Transients to 90V can occur when thenominal voltage range is 10V to 15V (ISO7637), along withbattery reversal in some cases. It’s fairly straightforwardto build automotive electronics around this system, butincreasingly end users want to operate portable electronics,such as GPS systems or music/video players,and to charge their Li-Ion batteries from the automotivebattery. To do so requires a compact, robust, effi cientand easy-to-design charging system

    标签: 464 USB DN 高效率

    上传时间: 2013-11-04

    上传用户:wfl_yy

  • DN458降压转换器简化低电压设计

      Many system designers need an easy way to producea negative 3.3V power supply. In systems that alreadyhave a transformer, one option is to swap out the existingtransformer with one that has an additional secondarywinding. The problem with this solution is that manysystems now use transformers that are standard, offthe-shelf components, and most designers want toavoid replacing a standard, qualifi ed transformer with acustom version. An easier alternative is to produce thelow negative voltage rail by stepping down an existingnegative rail. For example, if the system already employsan off-the-shelf transformer with two secondary windingsto produce ±12V, and a –3.3V rail is needed, a negativebuck converter can produce the –3.3V output from the–12V rail.

    标签: 458 DN 降压转换器 低电压

    上传时间: 2013-10-09

    上传用户:Jerry_Chow

  • VISHAY元器件应用

    Each year Vishay releases thousands of new components that enable our customers to create new and superior end products. We recognize that offering unique component solutions helps improve the performance of next-generation devices, overcome technical barriers, and create new markets.

    标签: VISHAY 元器件

    上传时间: 2013-12-14

    上传用户:ming529

  • 为敏感电路提供过压和电源反接保护

      What would happen if someone connected 24V to your12V circuits? If the power and ground lines were inadvertentlyreversed, would the circuits survive? Does yourapplication reside in a harsh environment, where the inputsupply can ring very high or even below ground? Evenif these events are unlikely, it only takes one to destroya circuit board.

    标签: 敏感电路 保护 过压 电源反接

    上传时间: 2013-10-26

    上传用户:jackandlee

  • LT1300和LT1301在功率DCDC转换器中的应用

      The design of battery-powered equipment can often bequite challenging. Since few ICs can operate directly fromthe end-of-life voltage from a 2-cell battery (about 1.8V),most systems require a DC/DCconverter. The systemdesigner often has a limited area in which to place the DC/DC converter; associated inductors and capacitors must be

    标签: LT 1300 1301 DCDC

    上传时间: 2013-11-23

    上传用户:wys0120

  • Circuitry for Single Cell Operation

      Portable, battery-powered operation of electronic apparatushas become increasingly desirable. Medical, remotedata acquisition, power monitoring and other applicationsare good candidates for batteryoperation. In some circumstances,due to space, power or reliability considerations,it is preferable to operate the circuitry from a single 1.5Vcell. Unfortunately, a 1.5V supply eliminates almost alllinear ICs as design candidates. In fact, the LM10 opamp-reference and the LT®1017/LT1018 comparators arethe only IC gain blocks fully specifi ed for 1.5V operation.Further complications are presented by the 600mV dropof silicon transistors and diodes. This limitation consumesa substantial portion of available supply range, makingcircuit design diffi cult. Additionally, any circuit designedfor 1.5V operation mustfunction at end-of-life batteryvoltage, typically 1.3V. (See Box Section, “Componentsfor 1.5V Operation.”)

    标签: Circuitry Operation Single Cell

    上传时间: 2013-10-30

    上传用户:hz07104032