今天，電視機與視訊轉換盒應用中的大多數調諧器采用的都是傳統單變換MOPLL概念。這種調諧器既能處理模擬電視訊號也能處理數字電視訊號，或是同時處理這兩種電視訊號(即所謂的混合調諧器)。在設計這種調諧器時需考慮的關鍵因素包括低成本、低功耗、小尺寸以及對外部組件的選擇。本文將介紹如何用英飛凌的MOPLL調諧芯片TUA6039-2或其影像版TUA6037實現超低成本調諧器參考設計。這種單芯片ULC調諧器整合了射頻和中頻電路，可工作在5V或3.3V，功耗可降低34%。設計采用一塊單層PCB，進一步降低了系統成本，同時能處理DVB-T/PAL/SECAM、ISDB-T/NTSC和ATSC/NTSC等混合訊號，可支持幾乎全球所有地區標準。圖1為采用TUA6039-2/TUA6037設計單變換調諧器架構圖。該調諧器實際上不僅是一個射頻調諧器，也是一個half NIM，因為它包括了中頻模塊。射頻輸入訊號透過一個簡單的高通濾波器加上中頻與民間頻段(CB)陷波器的組合電路進行分離。該設計沒有采用PIN二極管進行頻段切換，而是采用一個非常簡單的三工電路進行頻段切換。天線阻抗透過高感抗耦合電路變換至已調諧的輸入電路。然后透過英飛凌的高增益半偏置MOSFET BF5030W對預選訊號進行放大。BG5120K雙MOSFET可以用于兩個VHF頻段。在接下來的調諧后帶通濾波器電路中，則進行信道選擇和鄰道與影像頻率等多余訊號的抑制。前級追蹤陷波器和帶通濾波器的容性影像頻率補償電路就是專門用來抑制影像頻率。
上傳時間： 2013-11-21
上傳用戶：時代將軍
|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
上傳時間： 2013-12-10
上傳用戶：JIEWENYU
微電腦型單相交流集合式電表（單相二線系統） 特點： 精確度0.25%滿刻度±1位數 可同時量測與顯示交流電壓,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) 輸入與輸出絕緣耐壓 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) 主要規格： 精確度: 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) 輸入負載: <0.2VA (Voltage) <0.2VA (Current) 最大過載能力: 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 過載顯示: "doFL" 顯示值范圍: 0~600.0V(Voltage) 0~999.9Hz(Frequency)(<20% for voltage input) 0~19999 digit adjustable(Current,Watt,VA) 取樣時間: 2 cycles/sec. RS-485通訊位址: "01"-"FF" RS-485傳輸速度: 19200/9600/4800/2400 selective RS-485通信協議: Modbus RTU mode 溫度系數: 100ppm/℃ (0-50℃) 顯示幕: Red high efficiency LEDs high 10.16 mm(0.4") 參數設定方式: Touch switches 記憶型式: Non-volatile E²PROM memory 絕緣抗阻: >100Mohm with 500V DC 絕緣耐壓能力: 2KVac/1 min. (input/output/power) 1600 Vdc (input/output) 突波測試: ANSI c37.90a/1974,DIN-IEC 255-4 impulse voltage 4KV(1.2x50us) 使用環境條件: 0-50℃(20 to 90% RH non-condensed) 存放環境條件: 0-70℃(20 to 90% RH non-condensed) CE認證: EN 55022:1998/A1:2000 Class A EN 61000-3-2:2000 EN 61000-3-3:1995/A1:2001 EN 55024:1998/A1:2001
上傳時間： 2015-01-03
上傳用戶：幾何公差
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.
標簽： classification different document performs
上傳時間： 2015-03-03
上傳用戶：希醬大魔王
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.
標簽： object-oriented JILRuntime register supports
上傳時間： 2013-12-23
上傳用戶：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.
上傳時間： 2015-04-06
上傳用戶：zq70996813
mp3設計程序資料，采用c語言編寫。 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
上傳時間： 2015-04-13
上傳用戶：小碼農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).
標簽： multiplication Implement matrices matrix
上傳時間： 2014-08-30
上傳用戶：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.
標簽： that represents arguments the
上傳時間： 2015-07-22
上傳用戶：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.
標簽： T. eigenvalues tridiagonal eigenvalue
上傳時間： 2014-01-21
上傳用戶：CSUSheep
