虫虫首页| 资源下载| 资源专辑| 精品软件
登录| 注册

Second-Order

  • XAPP380 -利用CoolRunner-II CPLD创建交叉点开关

      This application note provides a functional description of VHDL source code for a N x N DigitalCrosspoint Switch. The code is designed with eight inputs and eight outputs in order to targetthe 128-macrocell CoolRunner™-II CPLD device but can be easily expanded to target higherdensity devices. To obtain the VHDL source code described in this document, go to sectionVHDL Code, page 5 for instructions.

    标签: CoolRunner-II XAPP CPLD 380

    上传时间: 2013-10-26

    上传用户:kiklkook

  • XAPP953-二维列序滤波器的实现

      This application note describes the implementation of a two-dimensional Rank Order filter. Thereference design includes the RTL VHDL implementation of an efficient sorting algorithm. Thedesign is parameterizable for input/output precision, color standards, filter kernel size,maximum horizontal resolution, and implementation options. The rank to be selected can bemodified dynamically, and the actual horizontal resolution is picked up automatically from theinput synchronization signals. The design has a fully synchronous interface through the ce, clk,and rst ports.

    标签: XAPP 953 二维 滤波器

    上传时间: 2013-12-14

    上传用户:逗逗666

  • 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: 2013-10-28

    上传用户:jyycc

  • 开关电源EMI设计(英文版)

    Integrated EMI/Thermal Design forSwitching Power SuppliesWei ZhangThesis submitted to the Faculty of theVirginia Polytechnic Institute and State Universityin partial fulfillment of the requirements for the degree of Integrated EMI/Thermal Design forSwitching Power SuppliesWei Zhang(ABSTRACT)This work presents the modeling and analysis of EMI and thermal performancefor switch power supply by using the CAD tools. The methodology and design guidelinesare developed.By using a boost PFC circuit as an example, an equivalent circuit model is builtfor EMI noise prediction and analysis. The parasitic elements of circuit layout andcomponents are extracted analytically or by using CAD tools. Based on the model, circuitlayout and magnetic component design are modified to minimize circuit EMI. EMI filtercan be designed at an early stage without prototype implementation.In the second part, thermal analyses are conducted for the circuit by using thesoftware Flotherm, which includes the mechanism of conduction, convection andradiation. Thermal models are built for the components. Thermal performance of thecircuit and the temperature profile of components are predicted. Improved thermalmanagement and winding arrangement are investigated to reduce temperature.In the third part, several circuit layouts and inductor design examples are checkedfrom both the EMI and thermal point of view. Insightful information is obtained.

    标签: EMI 开关电源 英文

    上传时间: 2013-11-16

    上传用户:萍水相逢

  • 基于EKF的异步电机直接转矩控制系统

    为了提高直接转矩控制(DTC)系统定子磁链估计精度,降低电流、电压测量的随机误差,提出了一种基于扩展卡尔曼滤波(EKF)实现异步电机转子位置和速度估计的方法。扩展卡尔曼滤波器是建立在基于旋转坐标系下由定子电流、电压、转子转速和其它电机参量所构成的电机模型上,将定子电流、定子磁链、转速和转子角位置作为状态变量,定子电压为输入变量,定子电流为输出变量,通过对磁链和转速的闭环控制提高定子磁链的估计精度,实现了异步电机的无速度传感器直接转矩控制策略,仿真结果验证了该方法的可行性,提高了直接转矩的控制性能。 Abstract:  In order to improve the Direct Torque Control(DTC) system of stator flux estimation accuracy and reduce the current, voltage measurement of random error, a novel method to estimate the speed and rotor position of asynchronous motor based on extended Kalman filter was introduced. EKF was based on d-p axis motor and other motor parameters (state vector: stator current, stator flux linkage, rotor angular speed and position; input: stator voltage; output: staror current). EKF was designed for stator flux and rotor speed estimation in close-loop control. It can improve the estimated accuracy of stator flux. It is possible to estimate the speed and rotor position and implement asynchronous motor drives without position and speed sensors. The simulation results show it is efficient and improves the control performance.

    标签: EKF 异步电机 直接转矩 控制系统

    上传时间: 2015-01-02

    上传用户:qingdou

  • 集合式直流电能表(小功率的)

    集合式直流电能表(小功率的) 特点: 精确度0.05%满刻度±1位数 可同时量测与显示/直流电压/电流/瓦特(千瓦)/瓦特小时(千瓦小时) 电压输入(DC0-99.99V/0-600.0V)自动变档功能 显示范围0-9999(电流/瓦特/千瓦),0至99999999(八位數瓦特小时)可任意规划 数位RS-485 界面 (Optional) 主要规格: 辅助电源消耗功率:<0.35VA(DC12V/DC24V) <0.5VA(DC48V) <1.5VA(AC90-240V(50/60Hz)) 精确度: 0.05% F.S. ±1 digit (23 ±5℃) 输入范围:Auto range(DC0-99.99V/0-600.0V(DC voltage)) 输入抗阻:>5MΩ(DC voltage) 取样时间:10 cycles/second(total) 过载显示: " doFL " 显示值范围: 0-9999 digit(DCA/W(KW)) 0-9999999.999 digit(WH/(KWH)) RS-485传输速度: 19200/9600/4800/2400 selective RS-485通讯位址: "01"-"FF"(0-255) RS-485通信协议: Modbus RTU mode 温度系数: 50ppm/℃ (0-50℃) 显示幕:Bight Red LEDs high 10.16 mm(0.4") 参数设定方式: Touch switches 记忆方式: Non-volatile E²PROM memory 绝缘耐压能力:2KVac/1min.(input/output)(RS-485(Isolating)) 1600 Vdc (input/output) (RS-485(Isolating)) 使用环境条件: 0-50℃(20 to 90% RH non-condensed) 存放环境条件: 0-70℃(20 to 90% RH non-condensed) CE认证: EN 55022:1998/A1:2000 Class A EN 61000-3-2:2000 EN 61000-3-3:1995/A1:2001 EN 55024:1998/A1:2001

    标签: 直流 电能表 小功率

    上传时间: 2013-11-20

    上传用户:s363994250

  • 高精度温度测量铂电阻温度探测器(PRTDs)和​​ADC

    Abstract: Many modern industrial, medical, and commercial applications require temperature measurements in the extended temperature rangewith accuracies of ±0.3°C or better, performed with reasonable cost and often with low power consumption. This article explains how platinumresistance temperature detectors (PRTDs) can perform measurements over wide temperature ranges of -200°C to +850°C, with absolute accuracyand repeatability better than ±0.3°C, when used with modern processors capable of resolving nonlinear mathematical equation quickly and costeffectively. This article is the second installment of a series on PRTDs. For the first installment, please read application note 4875, "High-Accuracy Temperature Measurements Call for Platinum Resistance Temperature Detectors (PRTDs) and Precision Delta-Sigma ADCs."

    标签: PRTDs ADC 高精度 温度测量

    上传时间: 2013-11-06

    上传用户:WMC_geophy

  • LT5514三阶互调的精确测量

      Accurate measurement of the third order intercept pointfor low distortion IC products such as the LT5514 requirescertain precautions to be observed in the test setup andtesting procedure. The LT5514 linearity performance ishigh enough to push the test equipment and test set-up totheir limits. A method for accurate measurement of thirdorder intermodulation products, IM3, with standard testequipment is outlined below.It is also important to correctly interpret the LT5514specification with respect to ROUT, and the impact ofdemo-board transmission-line termination loss whenevaluating the linearity performance, as explained in theLT5514 Datasheet and in Note 1 of this document.

    标签: 5514 LT 三阶互调 精确测量

    上传时间: 2013-11-14

    上传用户:l254587896

  • 本书由Java技术的创建者编写

    本书由Java技术的创建者编写,对Java 2平台标准版,V1.2中新增加的包及类进行了描述。本书主要由包概述和类描述构成。包概述对每个包及其所有类进行了简要描述,另外还画出了包中的类的继承层次结构示意图。每个类描述都独自构成一个小节,包含了类层次结构示意图、类描述、类示例、成员概述以及那些在版本1.2中作了修改或新增的类成员的描述。还详细说明了Java软件开发包(JDK)1.1到从版本1.2对类及方法所作的修改。需要指出的是:本书是补充版本,有些材料需要参阅《The Java Class Libraries, Second Edition, Volume 1》一书的内容。 本书是参考手册而不是指导手册,它不对Java语言进行解释。为了快速定位所需要的类或类成员的信息,本书按类的字母顺序组织。 本书由赵皑、黄志军、阳亮组织翻译,参加本书翻译的还有姚远、程子进、肖利平、刘永亮、薛亮、毛静萍、查海平、赵峰、郭树厢、曹波、肖斌、彭建明、郑欢。参加录入工作的有陈军、姜明、姜志明、张志荣等。 希望本书能够帮助Java程序员获取完整、专业和权威的信息,同时也希望本书能够帮助读者更全面地了解Java语言。由于水平有限和时间仓促,本书的翻译必定会存在一些纰漏,恳切希望广大读者批评指正。

    标签: Java 编写

    上传时间: 2014-01-27

    上传用户:cainaifa

  • Tug of War(A tug of war is to be arranged at the local office picnic. For the tug of war, the picnic

    Tug of War(A tug of war is to be arranged at the local office picnic. For the tug of war, the picnickers must be divided into two teams. Each person must be on one team or the other the number of people on the two teams must not differ by more than 1 the total weight of the people on each team should be as nearly equal as possible. The first line of input contains n the number of people at the picnic. n lines follow. The first line gives the weight of person 1 the second the weight of person 2 and so on. Each weight is an integer between 1 and 450. There are at most 100 people at the picnic. Your output will be a single line containing 2 numbers: the total weight of the people on one team, and the total weight of the people on the other team. If these numbers differ, give the lesser first. )

    标签: picnic the tug war

    上传时间: 2014-01-07

    上传用户:离殇