為了滿足現代高速通信中頻率快速轉換的需求,基于坐標旋轉數字計算(CORDIC,Coordinate Rotation Digital Computer)算法完成正交直接數字頻率合成(ODDFS,Orthogonal Direct Digital Frequency Synthesizer)電路設計方案。采用MATLAB和Xilinx System Generator開發工具搭建電路的系統模型,通過現場可編程門陣列(FPGA,Field Programmable Gate Array)完成電路的寄存器傳輸級(RTL,Register Transfer Level)驗證,仿真結果表明電路設計具有很高的有效性和可行性。
上傳時間: 2013-11-09
上傳用戶:hfnishi
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.
上傳時間: 2014-11-26
上傳用戶:Vici
A complete design for a data acquisition card for the IBM PC is detailed in this application note. Additionally, C language code is provided to allow sampling of data at speed of more than 20kHz. The speed limitation is strictly based on the execution speed of the "C" data acquisition loop. A "Turbo" XT can acquire data at speeds greater than 20kHz. Machines with 80286 and 80386 processors can go faster than 20kHz. The computer that was used as a test bed in this application was an XT running at 4.77MHz and therefore all system timing and acquisition time measurements are based on a 4.77MHz clock speed.
上傳時間: 2013-10-29
上傳用戶:BOBOniu
高速數字系統設計下載pdf:High-Speed Digital SystemDesign—A Handbook ofInterconnect Theory and DesignPracticesStephen H. HallGarrett W. HallJames A. McCallA Wiley-Interscience Publication JOHN WILEY & SONS, INC.New York • Chichester • Weinheim • Brisbane • Singapore • TorontoCopyright © 2000 by John Wiley & Sons, Inc.speeddigital systems at the platform level. The book walks the reader through everyrequired concept, from basic transmission line theory to digital timing analysis, high-speedmeasurement techniques, as well as many other topics. In doing so, a unique balancebetween theory and practical applications is achieved that will allow the reader not only tounderstand the nature of the problem, but also provide practical guidance to the solution.The level of theoretical understanding is such that the reader will be equipped to see beyondthe immediate practical application and solve problems not contained within these pages.Much of the information in this book has not been needed in past digital designs but isabsolutely necessary today. Most of the information covered here is not covered in standardcollege curricula, at least not in its focus on digital design, which is arguably one of the mostsignificant industries in electrical engineering.The focus of this book is on the design of robust high-volume, high-speed digital productssuch as computer systems, with particular attention paid to computer busses. However, thetheory presented is applicable to any high-speed digital system. All of the techniquescovered in this book have been applied in industry to actual digital products that have beensuccessfully produced and sold in high volume.Practicing engineers and graduate and undergraduate students who have completed basicelectromagnetic or microwave design classes are equipped to fully comprehend the theorypresented in this book. At a practical level, however, basic circuit theory is all thebackground required to apply the formulas in this book.
上傳時間: 2013-10-26
上傳用戶:縹緲
1.什么是CTP? CTP包括幾種含義: 脫機直接制版(Computer-to-plate) 在機直接制版(Computer-to-press) 直接印刷(Computer-to-paper/print) 數字打樣(Computer-to-proof) 普通PS版直接制版技術,即CTcP(Computer-to-conventional plate) 這里所論述的CTP系統是脫機直接制版(Computer-to-plate)。CTP就是計算機直接到印版,是一種數字化印版成像過程。CTP直接制版機與照排機結構原理相仿。起制版設備均是用計算機直接控制,用激光掃描成像,再通過顯影、定影生成直接可上機印刷的印版。計算機直接制版是采用數字化工作流程,直接將文字、圖象轉變為數字,直接生成印版,省去了膠片這一材料、人工拼版的過程、半自動或全自動曬版工序。
標簽: CTP
上傳時間: 2013-10-27
上傳用戶:baiom
PCI ExpressTM is the third generation of PCI (PeripheralComponent Interconnect) technology used to connect I/Operhipheral devices in computer systems. It is intended asa general purpose I/O device interconnect that meets theneeds of a wide variety of computing platforms such asdesktop, mobile, server and communications. It alsospecifies the electrical and mechanical attributes of thebackplane, connectors and removable cards in thesesystems.
上傳時間: 2013-11-17
上傳用戶:squershop
The LTC®4223 is a dual Hot Swap™ controller that meetsthe power requirements of the Micro TelecommunicationComputing Architecture (MicroTCA) specifi cation recentlyratifi ed by the PCI Industrial Computer ManufacturersGroup (PICMG).
上傳時間: 2013-10-21
上傳用戶:fengzimili
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.
上傳時間: 2013-11-05
上傳用戶:guobing703
應用 APPLICATIONS·電視機、錄像機、音頻設備、顯示器、復印機、打印裝置、游戲機及計算機等。·用于開關電源線性濾波器。·削除 TV、VTR、VCR及監聽器泄漏雜音。·用于OA 設備、通信設備和其它器件。·TV set, recorder, sound-frequency equipment, show-scope, photocopy-scope, typewrite equipment, recreation-scope, computer etc.·For line filters of switching power supplies.·Eliminates incoming/leaking noise of TVs, VTRs/VCRs and audio equipment .·For OA equipment, communications equipment and other electronic devices.
上傳時間: 2013-10-23
上傳用戶:shizhanincc
為了提高傳統溫度控制系統的性能,將PID控制理論與嵌入式系統相結合,采用瑞薩電子公司的H8S/2166作為核心處理器,AD公司的AD7705以及熱敏電阻溫度傳感器作為溫度檢測單元,利用4×6小鍵盤、LCD顯示器和S1D13305液晶控制器達到良好的人機交互,設計出了一個應用于化工領域的嵌入式實時溫度控制系統。相比于傳統溫度控制系統,該系統提供了更強的計算能力和可擴展能力,采用增量PID控制算法實現復雜控制。通過實驗,該系統能達到0.1 ℃的溫度控制精度以及小于120 s的溫度穩定時間。 Abstract: In order to improve the performance of conventional temperature control system, combining PID control theory with embedded systems, using the Renesas Electronics Corp. H8S/2166 micro-controller as a core processors, AD7705 and thermistor temperature sensor as a temperature detection unit and 4×6 small keyboard, LCD and S1D13305 LCD controller as a good human-computer interaction, this paper designed an embedded real-time temperature control system which is applied in chemical industry. Compared with conventional temperature control system, this system provides more computing power and extensibility, and adopts PID control algorithm for complex control. Through the experiment, the system can reach temperature control accuracy of 0.1 ℃ and temperature stabilization time of less than 120 seconds.
上傳時間: 2014-12-26
上傳用戶:003030