計算機應用中,有時需處理的信息不是數字量,而是一些隨時間連續變化的模擬量,甚至是一些非電量,如溫度、壓力、速度等。模擬量的存儲處理困難。首先將非電的模擬信號變成與之對應的模擬電信號,這要通過各種傳感器來完成。計算機可處理的信息均是數字量(電脈沖信號)1和0,必須把要處理的模擬電量轉換成數字化的電信號,這需要模擬(Analog)與數字(Digital)轉換電路。數字到模擬轉換:(Digital to Analog Convert, D/A) D/A轉換電路是模擬電路加上電子開關。D/A轉換電路的核心是一個運算放大器。運算放大器的特性:(Operation Amplifier) K->無窮大, V和->0 傳遞函數:V0 = -Vi * R0/Ri Ii->0, I和=If梯形R-2R電阻網絡D/A轉換器Ki受一個8位二進制代碼控制 某位為1,對應開關K倒向右邊; 某位為0,對應開關K倒向左邊。Ki不論倒向哪邊,均為接地VA-VH 的電位為: VREF,1/2VREF,..1/128VREFVO= -VREF *(1/2K7+1/4K6+…+1/256K0)V0= -(0-255/256)VREF 8位D/A轉換器DAC0830系列器件國家半導體公司(NS)產品,0830、0831、0832。R-2R梯形電阻網絡D/A轉換器,雙緩沖結構。單電源、低功耗、電流建立時間1uS。與微計算機接口方便。8位D/A轉換器DAC0830系列器件ILE: 輸入鎖存允許; WR1#: 加載IN REG; WR2#: 加載DAC REG; XFER#: IN REG傳到DAC REG; Iout1,Iout2: 外接OA輸入; Rfb: 反饋電阻接OA輸出; VREF: 參考電源,控制輸出電壓變化范圍。
標簽: AD轉換
上傳時間: 2013-10-16
上傳用戶:lu2767
PK51是為8051系列單片機所設計的開發工具,支持所有8051系列衍生產品,,支持帶擴展存儲器和擴展指令集(例如Dallas390/5240/400,Philips 51MX,Analog Devices MicroConverters)的新設備,以及支持很多公司的一流的設備和IP內核,比如Analog Devices, Atmel, Cypress Semiconductor, Dallas Semiconductor, Goal, Hynix, Infineon, Intel, NXP(founded by Philips), OKI, Silicon Labs,SMSC, STMicroeleectronics,Synopsis, TDK, Temic, Texas Instruments,Winbond等。通過PK51專業級開發工具,可以輕松地了解8051的On-chip peripherals與及其它關鍵特性。
上傳時間: 2013-10-09
上傳用戶:1109003457
The SDI standards are the predominant standards for uncompressed digital videointerfaces in the broadcast studio and video production center. The first SDI standard,SD-SDI, allowed standard-definition digital video to be transported over the coaxial cableinfrastructure initially installed in studios to carry analog video. Next, HD-SDI wasto support high-definition video. Finally, dual link HD-SDI and 3G-SDIdoubled the bandwidth of HD-SDI to support 1080p (50 Hz and 60 Hz) and other videoformats requiring more bandwidth than HD-SDI provides.
上傳時間: 2013-10-08
上傳用戶:yjj631
The LogiCORE™ GTP Wizard automates the task of creating HDL wrappers to configure the high-speed serial GTP transceivers in Virtex™-5 LXT and SXT devices. The menu-driven interface allows one or more GTP transceivers to be configured using pre-definedtemplates for popular industry standards, or from scratch, to support a wide variety of custom protocols.The Wizard produces a wrapper, an example design, and a testbench for rapid integration and verification of the serial interface with your custom function Features• Creates customized HDL wrappers to configureVirtex-5 RocketIO™ GTP transceivers• Users can configure Virtex-5 GTP transceivers toconform to industry standard protocols usingpredefined templates, or tailor the templates forcustom protocols• Included protocol templates provide support for thefollowing specifications: Aurora, CPRI, FibreChannel 1x, Gigabit Ethernet, HD-SDI, OBSAI,OC3, OC12, OC48, PCI Express® (PCIe®), SATA,SATA II, and XAUI• Automatically configures analog settings• Each custom wrapper includes example design, testbench; and both implementation and simulation scripts
標簽: Transceiver Virtex Wizar GTP
上傳時間: 2013-10-23
上傳用戶:leyesome
The field of microelectromechanical systems (MEMS), particularly micromachinedmechanical transducers, has been expanding over recent years, and the productioncosts of these devices continue to fall. Using materials, fabrication processes, anddesign tools originally developed for the microelectronic circuits industry, newtypes of microengineered device are evolving all the time—many offering numerousadvantages over their traditional counterparts. The electrical properties of siliconhave been well understood for many years, but it is the mechanical properties thathave been exploited in many examples of MEMS. This book may seem slightlyunusual in that it has four editors. However, since we all work together in this fieldwithin the School of Electronics and Computer Science at the University of Southampton,it seemed natural to work together on a project like this. MEMS are nowappearing as part of the syllabus for both undergraduate and postgraduate coursesat many universities, and we hope that this book will complement the teaching thatis taking place in this area.
上傳時間: 2013-10-16
上傳用戶:朗朗乾坤
A Computer-On-Module, or COM, is a Module with all components necessary for a bootable host computer, packaged as a super component. A COM requires a Carrier Board to bring out I/O and to power up. COMs are used to build single board computer solutions and offer OEMs fast time-to-market with reduced development cost. Like integrated circuits, they provide OEMs with significant freedom in meeting form-fit-function requirements. For all these reasons the COM methodology has gained much popularity with OEMs in the embedded industry. COM Express® is an open industry standard for Computer-On-Modules. It is designed to be future proof and to provide a smooth transition path from legacy parallel interfaces to LVDS (Low Voltage Differential Signaling) interfaces. These include the PCI bus and parallel ATA on the one hand and PCI Express and Serial ATA on the other hand.
上傳時間: 2013-11-05
上傳用戶:Wwill
第一章 虛擬儀器及labview入門 1.1 虛擬儀器概述 1.2 labview是什么? 1.3 labview的運行機制 1.3.1 labview應用程序的構成 1.3.2 labview的操作模板 1.4 labview的初步操作 1.4.1 創建VI和調用子VI 1.4.2 程序調試技術 1.4.3 子VI的建立 1.5 圖表(Chart)入門 第二章 程序結構 2.1 循環結構 2.1.1 While 循環 2.1.2 移位寄存器 2.1.3 For循環 2.2 分支結構:Case 2.3 順序結構和公式節點 2.3.1 順序結構 2.3.2 公式節點 第三章 數據類型:數組、簇和波形(Waveform) 3.1 數組和簇 3.2 數組的創建及自動索引 3.2.1 創建數組 3.2.2 數組控制對象、常數對象和顯示對象 3.2.3 自動索引 3.3 數組功能函數 3.4 什么是多態化(Polymorphism)? 3.5 簇 3.5.1 創建簇控制和顯示 3.5.2 使用簇與子VI傳遞數據 3.5.3 用名稱捆綁與分解簇 3.5.4 數組和簇的互換 3.6 波形(Waveform)類型 第四章 圖形顯示 4.1 概述 4.2 Graph控件 4.3 Chart的獨有控件 4.4 XY圖形控件(XY Graph) 4.5 強度圖形控件(Intensity Graph) 4.6 數字波形圖控件(Digital Waveform Graph) 4.7 3D圖形顯示控件(3D Graph) 第五章 字符串和文件I/ 5.1 字符串 5.2 文件的輸入/輸出(I/O) 5.2.1 文件 I/O 功能函數 5.2.2 將數據寫入電子表格文 5.3 數據記錄文件(datalog file) 第六章 數據采集 6.1 概述 6.1.1 采樣定理與抗混疊濾波器 6.1.2 數據采集系統的構成 6.1.3 模入信號類型與連接方式 6.1.4 信號調理 6.1.5 數據采集問題的復雜程度評估 6.2 緩沖與觸發 6.2.1 緩沖(Buffers) 6.2.2 觸發(Triggering) 6.3 模擬I/O(Analog I/O) 6.3.1 基本概念 6.3.2 簡單 Analog I/O 6.3.3 中級Analog I/O 6.4 數字I/O(Digital I/O) 6.5 采樣注意事項 6.5.1 采樣頻率的選擇 6.5.2 6.5.3 多任務環境 6.6 附:PCI-MIO-16E-4數據采集卡簡介 第七章 信號分析與處理 7.1 概述 7.2 信號的產生 7.3 標準頻率 7.4 數字信號處理 7.4.1 FFT變換 7.4.2 窗函數 7.4.3 頻譜分析 7.4.4 數字濾波 7.4.5 曲線擬合 第八章 labview程序設計技巧 8.1 局部變量和全局變量 8.2 屬性節點 8.3 VI選項設置 第九章 測量專題 9.1 概述 9.1.1 模入信號類型與連接方式 9.1.2 信號調理 9.2 電壓測量 9.3 頻率測量 9.4 相位測量 9.5 功率測量 9.6 阻抗測量 9.7 示波器 9.8 波形記錄與回放 9.9 元件伏安特性的自動測試 9.10 掃頻儀 9.11 函數發生器 9.12 實驗數據處理 9.13 頻域分析 9.14 時域分析 第十章 網絡與通訊 第十一章 儀器控制
上傳時間: 2013-11-06
上傳用戶:15070202241
Keil C51 V8 專業開發工具(PK51) PK51是為8051系列單片機所設計的開發工具,支持所有8051系列衍生產品,,支持帶擴展存儲器和擴展指令集(例如Dallas390/5240/400,Philips 51MX,Analog Devices MicroConverters)的新設備,以及支持很多公司的一流的設備和IP內核,比如Analog Devices, Atmel, Cypress Semiconductor, Dallas Semiconductor, Goal, Hynix, Infineon, Intel, NXP(founded by Philips), OKI, Silicon Labs,SMSC, STMicroeleectronics,Synopsis, TDK, Temic, Texas Instruments,Winbond等。 通過PK51專業級開發工具,可以輕松地了解8051的On-chip peripherals與及其它關鍵特性。 The PK51專業級開發工具包括… l μVision Ø 集成開發環境 Ø 調試器 Ø 軟件模擬器 l Keil 8051擴展編譯工具 Ø AX51宏匯編程序 Ø ANSI C編譯工具 Ø LX51 連接器 Ø OHX51 Object-HEX 轉換器 l Keil 8051編譯工具 Ø A51宏匯編程序 Ø C51 ANSI C編譯工具 Ø BL51 代碼庫連接器 Ø OHX51 Object-HEX 轉換器 Ø OC51 集合目標轉換器 l 目標調試器 Ø FlashMON51 目標監控器 Ø MON51目標監控器 Ø MON390 (Dallas 390)目標監控器 Ø MONADI (Analog Devices 812)目標監控器 Ø ISD51 在系統調試 l RTX51微實時內核 你應該考慮PK51開發工具包,如果你… l 需要用8051系列單片機來開發 l 需要開發 Dallas 390 或者 Philips 51MX代碼 l 需要用C編寫代碼 l 需要一個軟件模擬器或是沒有硬件仿真器 l 需要在單芯片上基于小實時內核創建復雜的應用
上傳時間: 2013-10-30
上傳用戶:yy_cn
Abstract: High-speed and low-speed data converters serve critical functions in modern broadband mobile radios. This application note outlines how todetermine high-speed data converter performance requirements in baseband sampling radio architectures. Also, system partition strategies andadvantages are outlined when considering a high-speed analog front-end (AFE) solution.
上傳時間: 2013-11-02
上傳用戶:jjj0202
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.
上傳時間: 2013-11-04
上傳用戶:lhll918