虫虫首页| 资源下载| 资源专辑| 精品软件
登录| 注册

ev-DO

EVDO(ev-DO)实际上是三个单词的缩写:Evolution(演进)、DataOnly。其全称为:CDMA20001xev-DO,是CDMA20001x演进(3G)的一条路径的一个阶段。这一路径有两个发展阶段,第一阶段叫1xev-DO,即“DataOnly”,它可以使运营商利用一个与IS-95或CDMA2000相同频宽的CDMA载频就可实现高达2.4Mbps的前向数据传输速率,已被国际电联ITU接纳为国际3G标准,并已具备商用化条件。第二阶段叫1xEV-DV。1xEV-DV意为“DataandVoice”,它可以在一个CDMA载频上同时支持话音和数据。
  • 提高在噪声环境下的磁卡读写器(MCR)系统

    Abstract: Most magnetic read head data sheets do not fully specify the frequency-dependent components andare often vague when specifying other key parameters. In some cases, the specifications of two very similarheads from two different manufacturers might be quite different in terms of parameters specified and omitted.The limitations in the data sheets make designing an optimum card reading system unnecessarily difficult andtime consuming. This document outlines a strategy to overcome the above shortcomings and offers guidelinesto overcome the noise issues.

    标签: MCR 噪声环境 磁卡读写器

    上传时间: 2013-11-13

    上传用户:dysyase

  • T2060_T2170打印头安装步骤

    Submission must be made within 10 days after the printhead upgrade.Failure to do so will void the 12-month warranty by TallyGenicom.

    标签: 2060 2170 打印头

    上传时间: 2013-11-22

    上传用户:DXM35

  • 确保电解电容器的寿命长-LED灯泡为例

    Abstract: Electrolytic capacitors are notorious for short lifetimes in high-temperature applications such asLED light bulbs. The careful selection of these devices with proper interpretation of their specifications isessential to ensure that they do not compromise the life of the end product. This application notediscusses this problem with electrolytic capacitors in LED light bulbs and provides an analysis that showshow it is possible to use electrolytics in such products.  

    标签: LED 电解电容器 寿命

    上传时间: 2013-11-17

    上传用户:asdfasdfd

  • 汽车电源转换面临的挑战

    摘要:随着功率密度和输出功率要求的不断提高,汽车市场中汽车功率调节设计面临更加严峻的挑战。多相DC-DC 转换器架构在许多方面简化了汽车设计。Intersil 推出的ISL78220 是专门为汽车起步/停车系统、车载音频系统和HEV/EV/燃料电池系统设计的多相升压控制器。该产品获得了TS16949 认证,体现了Intersil 致力于提高这些系统电源管理和模拟产品设计、制造和发布质量,促进汽车可靠性和能效达到最高水平。

    标签: 汽车电源 转换

    上传时间: 2013-10-13

    上传用户:lliuhhui

  • 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

  • 电流采样方法

    Sensing and/or controlling current flow is a fundamental requirement in many electronics systems, and the tech-niques to do so are as diverse as the applications them-selves.

    标签: 电流采样

    上传时间: 2013-10-15

    上传用户:daoyue

  • 快速,高效,独立型NiMH,NiCd电池充电

      Although recent popular attention is focused on LithiumIon batteries, one must not forget that other batterychemistries, such as Nickel Cadmium (NiCd) and NickelMetal Hydride (NiMH) have advantages in rechargeablepower systems. Nickel-based batteries are robust, capableof high discharge rates, have good cycle life, do notrequire special protection circuitry and are less expensivethan Li-Ion. Among the two, NiMH batteries are rapidlyreplacing NiCd because of their higher capacity (40% to50% more) and the environmental concerns of the toxiccadmium contained in NiCd batteries.

    标签: NiMH NiCd 独立 电池充电

    上传时间: 2013-11-04

    上传用户:qq10538412

  • 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

  • 威柏EV电动汽车电驱DC-LINK电容

    DC-link Automotive: MKP1849 (Customized)电动汽车电驱直流母线电容(顾客订制品)MKP1849系列.MKP1849-可集成母线排,大大降低了寄生电感,提高了系统稳定性。

    标签: DC-LINK 电动汽车 电容

    上传时间: 2013-10-13

    上传用户:nanfeicui

  • 基于FPGA的高度集成DCDC稳压器

      In a recent discussion with a system designer, the requirementfor his power supply was to regulate 1.5Vand deliver up to 40A of current to a load that consistedof four FPGAs. This is up to 60W of power that must bedelivered in a small area with the lowest height profi lepossible to allow a steady fl ow of air for cooling. Thepower supply had to be surface mountable and operateat high enough effi ciency to minimize heat dissipation.He also demanded the simplest possible solution so histime could be dedicated to the more complex tasks. Asidefrom precise electrical performance, this solution had toremovethe heat generated during DC to DC conversionquickly so that the circuit and the ICs in the vicinity do notoverheat. Such a solution requires an innovative designto meet these criteria:

    标签: FPGA DCDC 集成 稳压器

    上传时间: 2013-11-24

    上传用户:defghi010