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  • 双绞线和低通滤波器降低EMI_RFI

    Abstract: Alexander Graham Bell patented twisted pair wires in 1881. We still use them today because they work so well. In addition we have the advantage ofincredible computer power within our world. Circuit simulators and filter design programs are available for little or no cost. We combine the twisted pair and lowpassfilters to produce spectacular rejection of radio frequency interference (RFI) and electromagnetic interference (EMI). We also illustrate use of a precision resistorarray to produce a customizable differential amplifier. The precision resistors set the gain and common mode rejection ratios, while we choose the frequencyresponse.

    标签: EMI_RFI 双绞线 低通滤波器

    上传时间: 2014-11-26

    上传用户:Vici

  • 信号链和PLC是如何影响我们的生活

    Abstract: It is incredible how many programmable logic controls (PLCs) around us make our modern life possible and pleasant.Machines in our homes heat and cool our air and water, as well as preserve and cook our food. This tutorial explains the importanceof PLCs, and describes how to choose component parts using the parametric tools on the Maxim's website.A similar version of this article was published February 29, 2012 in John Day's Automotive Electronic News.

    标签: PLC 信号链

    上传时间: 2013-11-10

    上传用户:liaocs77

  • 智能电网安全保护

    Abstract: Stuxnet, a sophisticated virus that damaged Iran's nuclear capability, should be an eye openerfor the world. We can choose to learn something very narrow (how to combat the Stuxnet virus) or wecan choose to focus on the larger goal of thwarting the next type of creative cyber attack. Unfortunately,critical industrial infrastructure is not currently designed with security as a key goal, leaving open multipleavenues for an educated and funded attacker to create massive problems. This tutorial outlines somebasic concepts that engineers and product definers should consider to make sure their new projects stayahead of future threats.

    标签: 智能电网 安全保护

    上传时间: 2013-11-17

    上传用户:llwap

  • DN442 I2C可控降压紧凑型同步DC/DC稳压器

      The LTC®3562 quad output step-down regulator is designedfor multicore handheld microprocessor applications thatoperate from a single Li-Ion battery. Its four monolithic, higheffi ciency buck regulators support Intel’s mobile CPU P-Stateand C-State energy saving operating modes. The outputvoltages are independently controllable via I2C, and eachoutput can be independently started and shut down. Designerscan choose from power saving pulse-skipping mode orBurst Mode® operation, or select low noise LDO mode. Thespace-saving LTC3562 is available in a 3mm × 3mm QFNpackage and requires few external components.

    标签: DC 442 I2C DN

    上传时间: 2013-10-07

    上传用户:1583060504

  • Wide-input dc/dc modules offer

    When a system designer specifies a nonisolated dc/dc powermodule, considering the needed input voltage range isequally as important as considering the required performanceattributes and features. Generally, nonisolated moduleshave either a narrow or a wide input voltage range. Narrowinputmodules typically have a nominal input voltage of3.3, 5, or 12 V. For systems that operate from a tightlyregulated input bus—such as those that do not use batterybackup—a narrow-input module is often adequate sincethe input remains fairly stable.Offering greater flexibility, wide-input modules operatewithin a range of 7 to 36 V, which includes the popular12- or 24-V industrial bus. This enables a single module tobe used for generating multiple voltages. These modulesare ideal for industrial controls, HVAC systems, vehicles,medical instrumentation, and other applications that usea loosely regulated distribution bus. In addition, systemspowered by a rectifier/battery charger with lead-acidbattery backup almost always require wide-input modules.System designers who choose power supplies may wantto take a close look at the latest generation of wide-inputdc/dc modules.

    标签: Wide-input modules offer dc

    上传时间: 2014-12-24

    上传用户:dragonhaixm

  • lpc2478完全使用手册

    NXP Semiconductor designed the LPC2400 microcontrollers around a 16-bit/32-bitARM7TDMI-S CPU core with real-time debug interfaces that include both JTAG andembedded Trace. The LPC2400 microcontrollers have 512 kB of on-chip high-speedFlash memory. This Flash memory includes a special 128-bit wide memory interface andaccelerator architecture that enables the CPU to execute sequential instructions fromFlash memory at the maximum 72 MHz system clock rate. This feature is available onlyon the LPC2000 ARM Microcontroller family of products. The LPC2400 can execute both32-bit ARM and 16-bit Thumb instructions. Support for the two Instruction Sets meansEngineers can choose to optimize their application for either performance or code size atthe sub-routine level. When the core executes instructions in Thumb state it can reducecode size by more than 30 % with only a small loss in performance while executinginstructions in ARM state maximizes core performance.

    标签: 2478 lpc 使用手册

    上传时间: 2013-11-15

    上传用户:zouxinwang

  • 基于CPLD的QDPSK调制解调电路设计

    为了在CDMA系统中更好地应用QDPSK数字调制方式,在分析四相相对移相(QDPSK)信号调制解调原理的基础上,设计了一种QDPSK调制解调电路,它包括串并转换、差分编码、四相载波产生和选相、相干解调、差分译码和并串转换电路。在MAX+PLUSⅡ软件平台上,进行了编译和波形仿真。综合后下载到复杂可编程逻辑器件EPM7128SLC84-15中,测试结果表明,调制电路能正确选相,解调电路输出数据与QDPSK调制输入数据完全一致,达到了预期的设计要求。 Abstract:  In order to realize the better application of digital modulation mode QDPSK in the CDMA system, a sort of QDPSK modulation-demodulation circuit was designed based on the analysis of QDPSK signal modulation-demodulation principles. It included serial/parallel conversion circuit, differential encoding circuit, four-phase carrier wave produced and phase chosen circuit, coherent demodulation circuit, difference decoding circuit and parallel/serial conversion circuit. And it was compiled and simulated on the MAX+PLUSⅡ software platform,and downloaded into the CPLD of EPM7128SLC84-15.The test result shows that the modulation circuit can exactly choose the phase,and the output data of the demodulator circuit is the same as the input data of the QDPSK modulate. The circuit achieves the prospective requirement of the design.

    标签: QDPSK CPLD 调制解调 电路设计

    上传时间: 2014-01-13

    上传用户:qoovoop

  • 6小时学会labview

    6小时学会labview, labview Six Hour Course – Instructor Notes   This zip file contains material designed to give students a working knowledge of labview in a 6 hour timeframe. The contents are: Instructor Notes.doc – this document. labviewIntroduction-SixHour.ppt – a PowerPoint presentation containing screenshots and notes on the topics covered by the course. Convert C to F (Ex1).vi – Exercise 1 solution VI. Convert C to F (Ex2).vi – Exercise 2 solution subVI. Thermometer-DAQ (Ex2).vi – Exercise 2 solution VI. Temperature Monitor (Ex3).vi – Exercise 3 solution VI. Thermometer (Ex4).vi – Exercise 4 solution subVI. Convert C to F (Ex4).vi – Exercise 4 solution subVI. Temperature Logger (Ex4).vi – Exercise 4 solution VI. Multiplot Graph (Ex5).vi – Exercise 5 solution VI. Square Root (Ex6).vi – Exercise 6 solution VI. State Machine 1 (Ex7).vi – Exercise 7 solution VI.   The slides can be presented in two three hour labs, or six one hour lectures. Depending on the time and resources available in class, you can choose whether to assign the exercises as homework or to be done in class. If you decide to assign the exercises in class, it is best to assign them in order with the presentation. This way the students can create VI’s while the relevant information is still fresh. The notes associated with the exercise slide should be sufficient to guide the students to a solution. The solution files included are one possible solution, but by no means the only solution.

    标签: labview

    上传时间: 2013-10-13

    上传用户:zjwangyichao

  • MAX16948双遥控天线LDO开关

      Abstract: This application note helps system designers choose the correct external components for use with the MAX16948 dualremote antenna LDO/switch, thus ensuring that automobile-regulated phantom antenna supply and output-current-monitoring circuitrymeet performance objectives. An electronic calculator is provided that helps specify the critical external components for theMAX16948, thus reducing design time. The calculator also determines the device's analog output voltage, output current-limitthreshold, and output current-sensing accuracies. The calculator includes new automatic Step By Step feature that assists designerswith component choice. To use the new automatic feature, click on the Step By Step button relative to the desired section.

    标签: 16948 MAX LDO 遥控天线

    上传时间: 2013-11-04

    上传用户:lhll918

  • ZigBee无线传感网络的路由协议研究

     为满足无线网络技术具有低功耗、节点体积小、网络容量大、网络传输可靠等技术要求,设计了一种以MSP430单片机和CC2420射频收发器组成的无线传感节点。通过分析其节点组成,提出了ZigBee技术中的几种网络拓扑形式,并研究了ZigBee路由算法。针对不同的传输要求形式选用不同的网络拓扑形式可以尽大可能地减少系统成本。同时针对不同网络选用正确的ZigBee路由算法有效地减少了网络能量消耗,提高了系统的可靠性。应用试验表明,采用ZigBee方式通信可以提高传输速率且覆盖范围大,与传统的有线通信方式相比可以节约40%左右的成本。 Abstract:  To improve the proposed technical requirements such as low-ower, small nodes, large capacity and reliable network transmission, wireless sensor nodes based on MSP430 MCU and CC2420 RF transceiver were designed. This paper provided network topology of ZigBee technology by analysing the component of the nodes and researched ZigBee routing algorithm. Aiming at different requirements of transmission mode to choose the different network topologies form can most likely reduce the system cost. And aiming at different network to choose the correct ZigBee routing algorithm can effectively reduced the network energy consumption and improved the reliability of the system. Results show that the communication which used ZigBee mode can improve the transmission rate, cover more area and reduce 40% cost compared with traditional wired communications mode.

    标签: ZigBee 无线传感网络 协议研究 路由

    上传时间: 2013-10-09

    上传用户:robter