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  • 智能电网安全性

    Abstract: The rapid build out of today's smart grid raises a number of security questions. In this article,we review two recent well-documented security breaches and a report of a security gap. These situationsinclude a 2009 smart-meter hack in Puerto Rico; a 2012 password discovery in grid distributionequipment; and insecure storage of a private key in distribution automation equipment. For each of theseattacks, we examine the breach, the potential threat, and secure silicon methods that, as part of acomplete security strategy, can help thwart the attacks.

    标签: 智能电网 安全性

    上传时间: 2013-10-27

    上传用户:tecman

  • LED的电源管理

    A light-emitting diode (LED) is a semiconductor device that emits narrow-spectrum incoherent light when forward-biased.The color of the emitted light depends on the chemical composition of the semiconductor material used, and can benear-ultraviolet, visible or infrared. LEDs are more prevalent today than ever before, replacing traditional incandescent andfluorescent bulbs in many lighting applications. Incandescents use a heated filament, are subject to breakage and burnoutand operate at a luminous efficiency of 2% to 4%. Fluorescents are more efficient, at 7% to 12%, but require highdrive voltage and contain mercury, a toxic substance that may be eventually banned in certain countries. LEDs, however,produce light directly through electroluminescence, operate at low voltage and can deliver over 20% luminous efficiency.

    标签: LED 电源管理

    上传时间: 2013-11-07

    上传用户:xiaoyuer

  • 高功率PoE PD接口与集成反激式控制器

      To this day, Power over Ethernet (PoE) continues to gainpopularity in today’s networking world. The 12.95Wdelivered to the Powered Device (PD) input supplied bythe Power Sourcing Equipment (PSE) is a universal supply.Each PD provides its own DC/DC conversion from anominal 48V supply, thus eliminating the need for a correctvoltage wall adapter. However, higher power devicescan not take advantage of standard PoE because of itspower limitations, and must rely on a large wall adapteras their primary supply. The new LTC4268-1 breaks thispower barrier by allowing for power of up to 35W for suchpower-hungry 2-pair PoE applications. The LTC4268-1provides a complete solution by integrating a high powerPD interface control with an isolated fl yback controller.

    标签: PoE 高功率 PD接口 集成

    上传时间: 2014-12-24

    上传用户:jasson5678

  • 两相同步降压型控制器具有轻负载逐级递减模式

      today’s computer, datacom, and telecom systems demandpower supplies that are effi cient, respond quicklyto load transients and accurately regulate the voltageat the load. For example, load current can be measuredby using the inductor DCR, thus eliminating the needfor a dedicated sense resistor. Inductor DCR sensingincreases effi ciency—especially at heavy load—whilereducing component cost and required board space.The LTC®3856 single-output 2-phase synchronous buckcontroller improves the accuracy of inductor DCR sensingby compensating for changes in DCR due to temperature.

    标签: 同步降压型 控制器 负载

    上传时间: 2013-11-05

    上传用户:guobing703

  • LTC1325电池管理IC的使用

      For a variety of reasons, it is desirable to charge batteriesas rapidly as possible. At the same time, overchargingmust be limited to prolong battery life. Such limitation ofovercharging depends on factors such as the choice ofcharge termination technique and the use of multi-rate/multi-stage charging schemes. The majority of batterycharger ICs available today lock the user into one fixedcharging regimen, with at best a limited number ofcustomization options to suit a variety of application needsor battery types. The LTC®1325 addresses these shortcomingsby providing the user with all the functionalblocks needed to implement a simple but highly flexiblebattery charger (see Figure 1) which not only addressesthe issue of charging batteries but also those of batteryconditioning and capacity monitoring.

    标签: 1325 LTC IC的 电池管理

    上传时间: 2013-10-19

    上传用户:royzhangsz

  • 基于PIC16C711的脉冲点火控制器设计

     针对目前燃气灶市场的状况,提出一种基于PIC16C711单片机的燃气灶脉冲点火控制器设计,具体包括有系统的组成和功能介绍、硬件电路设计及软件功能实现。 Abstract:  Aiming at today’s gas cooker market, a pulse ignition controler design based on PIC16C711 is presented.The specific descriptions of system components and functions,hardware circuit design and software function are given.

    标签: C711 PIC 16C 711

    上传时间: 2013-10-31

    上传用户:zhqzal1014

  • LLCR Pin Socket Testing with t

    LLCR Pin Socket Testing with the Model 3732 High Density Matrix Card Computer processors (CPUs) today have come a long way from the computer processors of the past. They draw more power, run at lower voltages, and have more pins than ever before.

    标签: Testing Socket LLCR with

    上传时间: 2013-10-24

    上传用户:whenfly

  • 87C576微控制器的在线编程

    The 87C576 includes two separate methods of programming theEPROM array, the traditional modified Quick-Pulse method, and anew On-Board Programming technique (OBP).Quick Pulse programming is a method using a number of devicepins in parallel (see Figure 1) and is the traditional way in which87C51 family members have been programmed. The Quick-Pulsemethod supports the following programming functions:– program USER EPROM– verify USER EPROM– program KEY EPROM– program security bits– verify security bits– read signature bytesThe Quick-Pulse method is quite easily suited to standardprogramming equipment as evidenced by the numerous vendors of87C51 compatible programmers on the market today. Onedisadvantage is that this method is not well suited to programming inthe embedded application because of the large number of signallines that must be isolated from the application. In addition, parallelsignals from a programmer would need to be cabled to theapplication’s circuit board, or the application circuit board wouldneed to have logic built-in to perform the programming functions.These requirements have generally made in-circuit programmingusing the modified Quick Pulse method impractical in almost all87C51 family applications.

    标签: 87C576 微控制器 编程

    上传时间: 2013-10-21

    上传用户:xiaozhiqban

  • 《器件封装用户向导》赛灵思产品封装资料

    Introduction to Xilinx Packaging Electronic packages are interconnectable housings for semiconductor devices. The major functions of the electronic packages are to provide electrical interconnections between the IC and the board and to efficiently remove heat generated by the device. Feature sizes are constantly shrinking, resulting in increased number of transistors being packed into the device. today's submicron technology is also enabling large-scale functional integration and system-on-a-chip solutions. In order to keep pace with these new advancements in silicon technologies, semiconductor packages have also evolved to provide improved device functionality and performance. Feature size at the device level is driving package feature sizes down to the design rules of the early transistors. To meet these demands, electronic packages must be flexible to address high pin counts, reduced pitch and form factor requirements. At the same time,packages must be reliable and cost effective.

    标签: 封装 器件 用户 赛灵思

    上传时间: 2013-10-22

    上传用户:ztj182002

  • wp379 AXI4即插即用IP

    In the past decade, the size and complexity of manyFPGA designs exceeds the time and resourcesavailable to most design teams, making the use andreuse of Intellectual Property (IP) imperative.However, integrating numerous IP blocks acquiredfrom both internal and external sources can be adaunting challenge that often extends, rather thanshortens, design time. As today's designs integrateincreasing amounts of functionality, it is vital thatdesigners have access to proven, up-to-date IP fromreliable sources.

    标签: AXI4 379 wp 即插即用

    上传时间: 2013-11-15

    上传用户:lyy1234