今天，电视机与视讯转换盒应用中的大多数调谐器采用的都是传统单变换MOPLL概念。这种调谐器既能处理模拟电视讯号也能处理数字电视讯号，或是同时处理这两种电视讯号(即所谓的混合调谐器)。在设计这种调谐器时需考虑的关键因素包括低成本、低功耗、小尺寸以及对外部组件的选择。本文将介绍如何用英飞凌的MOPLL调谐芯片TUA6039-2或其影像版TUA6037实现超低成本调谐器参考设计。这种单芯片ULC调谐器整合了射频和中频电路，可工作在5V或3.3V，功耗可降低34%。设计采用一块单层PCB，进一步降低了系统成本，同时能处理DVB-T/PAL/SECAM、ISDB-T/NTSC和ATSC/NTSC等混合讯号，可支持几乎全球所有地区标准。图1为采用TUA6039-2/TUA6037设计单变换调谐器架构图。该调谐器实际上不仅是一个射频调谐器，也是一个half NIM，因为它包括了中频模块。射频输入讯号透过一个简单的高通滤波器加上中频与民间频段(CB)陷波器的组合电路进行分离。该设计没有采用PIN二极管进行频段切换，而是采用一个非常简单的三工电路进行频段切换。天线阻抗透过高感抗耦合电路变换至已调谐的输入电路。然后透过英飞凌的高增益半偏置MOSFET BF5030W对预选讯号进行放大。BG5120K双MOSFET可以用于两个VHF频段。在接下来的调谐后带通滤波器电路中，则进行信道选择和邻道与影像频率等多余讯号的抑制。前级追踪陷波器和带通滤波器的容性影像频率补偿电路就是专门用来抑制影像频率。
上传时间： 2013-11-21
上传用户：时代将军
|Introduction Basic Concept Tips to layout Power circuit Type of Power circuit Basic Concept Maximum Current calculation Resistance of Copper ideal power supply & noise Capacitor & Inductor Power consumption Function of power circuit
上传时间： 2013-12-10
上传用户：JIEWENYU
微电脑型单相交流集合式电表（单相二线系统） 特点： 精确度0.25%满刻度±1位数 可同时量测与显示交流电压,電流,頻率,瓦特,(功率因數/視在功率) 交流電壓,電流,瓦特皆為真正有效值(TRMS) 交流電流,瓦特之小數點可任意設定 瓦特單位W或KW可任意設定 CT比可任意設定(1至999) 輸入與輸出絕緣耐压 2仟伏特/1分鐘( 突波測試強度4仟伏特(1.2x50us) 數位RS-485界面 (Optional) 主要规格： 精确度: 0.1% F.S.±1 digit (Frequency) 0.25% F.S.±1 digit(ACA,ACV,Watt,VA) 0.25% F.S. ±0.25o(Power Factor) (-.300~+.300) 输入负载: <0.2VA (Voltage) <0.2VA (Current) 最大过载能力: Current related input: 3 x rated continuous 10 x rated 30 sec. 25 x rated 3sec. 50 x rated 1sec. Voltage related input: maximum 2 x rated continuous 过载显示: "doFL" 显示值范围: 0~600.0V(Voltage) 0~999.9Hz(Frequency)(<20% for voltage input) 0~19999 digit adjustable(Current,Watt,VA) 取样时间: 2 cycles/sec. RS-485通讯位址: "01"-"FF" RS-485传输速度: 19200/9600/4800/2400 selective RS-485通信协议: Modbus RTU mode 温度系数: 100ppm/℃ (0-50℃) 显示幕: Red high efficiency LEDs high 10.16 mm(0.4") 参数设定方式: Touch switches 记忆型式: Non-volatile E²PROM memory 绝缘抗阻: >100Mohm with 500V DC 绝缘耐压能力: 2KVac/1 min. (input/output/power) 1600 Vdc (input/output) 突波测试: ANSI c37.90a/1974,DIN-IEC 255-4 impulse voltage 4KV(1.2x50us) 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
上传时间： 2015-01-03
上传用户：几何公差
Rainbow is a C program that performs document classification usingone of several different methods, including naive Bayes, TFIDF/Rocchio,K-nearest neighbor, Maximum Entropy, Support Vector Machines, Fuhr sProbabilitistic Indexing, and a simple-minded form a shrinkage withnaive Bayes.
标签： classification different document performs
上传时间： 2015-03-03
上传用户：希酱大魔王
JILRuntime A general purpose, register based virtual machine (VM) that supports object-oriented features, reference counting (auto destruction of data as soon as it is no longer used, no garbage collection), exceptions (handled in C/C++ or virtual machine code) and other debugging features. Objects and functions can be written in virtual machine code, as well as in C or C++, or any other language that can interface to C object code. The VM is written for maximum performance and thus is probably not suitable for embedded systems where a small memory footprint is required. Possible uses of the VM are in game development, scientific research, or to provide a stand-alone, general purpose programming environment.
标签： object-oriented JILRuntime register supports
上传时间： 2013-12-23
上传用户：cc1015285075
*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ** RELEASE NOTES *** *** *** *** ***** *** *** *** *** *** *** *** *** *** *** *** *** *** 1) RELEASE NOTES: --- --- ---- The release notes are now provided in PDF format in the file: \SOFTWARE\uCOS-II\DOC\RelV251.PDF 2) FEATURES SINCE V2.00: --- --- --- ----- All the features added since V2.00 are described in the PDF file: \SOFTWARE\uCOS-II\DOC\NewV251.PDF 3) EVENT FLAGS: -------------- Event Flags are discussed in AN-1007 (see www.Micrium.com/app_notes.htm) 4) QUICK REFERENCE CHART: ------------------------ A Quick Reference Chart for all the functions in V2.51 is provided in the following .PDF files: \SOFTWARE\uCOS-II\DOC\QuickRefChartV251-Color.PDF Once printed, simply FOLD the page in half and if you have a LAMINATION machine, you can protect the chart by laminating it.
上传时间： 2015-04-06
上传用户：zq70996813
mp3设计程序资料，采用c语言编写。 README file for yampp-3 source code 2001-05-27 This is the current state of the yampp-3 source code, 2001-05-27. This code is intended to run on Rev. B of the yampp-3 PCB, but can ofcourse be used on compatible systems as well. It still uses the "old" song selection system as the yampp-2. However, the disk handling routines has improved a lot and the obviosly, the new VS1001 handling has been put in. The codesize is almost at it s maximum at 1F40 bytes. A .ROM file is included if you don t have the compiler set up. For now, the documentation is in the code
上传时间： 2015-04-13
上传用户：小码农lz
ARM下 Implement matrix multiplication of 2 square matrices, with data read from an input file and printed both to the console and to an output file. • Assume a file with correct data (no garbage, characters, etc.). • you must check and provide appropriate execution for 2 extra cases, namely when the matrix size given is either “0” , or when the size is greater than the maximum handled of “5” . In these 2 cases you must implement the following behaviour: o If size = 0, then print a message “Size = 0 is unacceptable” and continue by reading the next size for the next 2 matrices (if not end of file). o If size >5, then print two messages: “Size is too big - unacceptable”. Then read and discard the next (size2 ) integers and continue by reading the next size for the next 2 matrices (if not end of file).
标签： multiplication Implement matrices matrix
上传时间： 2014-08-30
上传用户：dsgkjgkjg
a program that takes in three arguments: the first one represents the size of an array that will be created the second one represents the maximum value that each of the array elements can have the third one represents the position in the array that you would like to print the value of.
标签： that represents arguments the
上传时间： 2015-07-22
上传用户：waitingfy
computes the eigenvalues of a symmetric tridiagonal * matrix T. The user may ask for all eigenvalues, all eigenvalues in the half-open interval (VL, VU], or the IL-th through IU-th eigenvalues.
标签： T. eigenvalues tridiagonal eigenvalue
上传时间： 2014-01-21
上传用户：CSUSheep
