Many system designers need an easy way to producea negative 3.3V power supply. In systems that alreadyhave a transformer, one option is to swap out the existingtransformer with one that has an additional secondarywinding. The problem with this solution is that manysystems now use transformers that are standard, offthe-shelf components, and most designers want toavoid replacing a standard, qualifi ed transformer with acustom version. An easier alternative is to produce thelow negative voltage rail by stepping down an existingnegative rail. For example, if the system already employsan off-the-shelf transformer with two secondary windingsto produce ±12V, and a –3.3V rail is needed, a negativebuck converter can produce the –3.3V output from the–12V rail.
上傳時間： 2013-10-09
上傳用戶：Jerry_Chow
鎖定放大是微弱信號檢測的重要手段?；谙嚓P檢測理論，利用開關電容的開關實現鎖定放大器中乘法器的功能，提出開關電容和積分器相結合以實現相關檢測的方法，并設計出一種鎖定放大器。該鎖定放大器將微弱信號轉化為與之相關的方波，通過后續電路得到正比于被測信號的直流電平，為后續采集處理提供方便。測量數據表明鎖定放大器前級可將10-6 A的電流轉換為10-1 V的電壓，后級通過帶通濾波器級聯可將信號放大1×105倍。該方法在降低噪聲的同時，可對微弱信號進行放大，線性度較高、穩定性較好。 Abstract: Lock-in Amplifying（LIA）is one of important means for weak signal detection. Based on cross-correlation detection theory， switch in the swithched capacitor was used as multiplier of LIA， and a new method of correlation detection was proposed combining swithched capacitor with integrator. A kind of LIA was designed which can convert the weak signal to square-wave， then DC proportional to measured signal was obtained through follow-up conditioning circuit， providing convenience for signal acquisition and processing. The measured data shows that the electric current（10-6 A） can be changed into voltage（10-1 V） by LIA， and the signal is magnified 1×105 times by cascade band-pass filter. The noise is suppressed and the weak signal is amplified. It has the advantages of good linearity and stability.
上傳時間： 2013-11-29
上傳用戶：黑漆漆
畢業設計 USB TO Gigabit LAN 網卡 隨著網絡技術飛速發展，多媒體的應用越來越多，人們對網絡的要求也越來越高，為了適應市場的需求，網卡出現了。它以其結構簡單、成本低廉、兼容性強等諸多的優越性得到了廣泛的應用。由于網絡的應用越來越廣泛，網卡的應用也越來越多、功能越來越強大。開始時由于技術方面的限制，網卡只有10Mbps的吞吐量，由于網絡技術的發展，100Mbps吞吐量的網卡開始在市場上得到廣泛的應用。而現在1000Mbps吞吐量的網卡的出現又給網絡的傳輸帶來了新的活力。 論文中主要闡述了基于以太網的USB TO Gigabit LAN網卡的設計與制作。論文首先對以太網進行了介紹，緊接著講了網卡的基本知識。隨后又對USB TO Gigabit LAN網卡的電路設計和制作進行了詳細的描述。論文還包括了USB TO Gigabit LAN網卡的調試等內容。
上傳時間： 2014-12-02
上傳用戶：wab1981
PICKIT™ 2 PROGRAMMER-TO-GO USER GUIDE The PICkit 2 Programmer-To-Go functionality allows a PIC MCU memory image to be downloaded into the PICkit 2 unit for later programming into a specific PIC MCU. No software or PC is required to program devices once the PICkit 2 unit is set up for Programming-To-Go. A USB power source for the PICkit 2 is all that is needed.
標簽： PROGRAMMER-TO PICKIT 8482
上傳時間： 2013-10-29
上傳用戶：ca05991270
The PCA9541 is a 2-to-1 I2C-bus master selector designed for high reliability dual masterI2C-bus applications where system operation is required, even when one master fails orthe controller card is removed for maintenance. The two masters (for example, primaryand back-up) are located on separate I2C-buses that connect to the same downstreamI2C-bus slave devices. I2C-bus commands are sent by either I2C-bus master and are usedto select one master at a time. Either master at any time can gain control of the slavedevices if the other master is disabled or removed from the system. The failed master isisolated from the system and will not affect communication between the on-line masterand the slave devices on the downstream I2C-bus.
上傳時間： 2013-10-09
上傳用戶：3294322651
The MAX3243E device consists of three line drivers, five line receivers, and a dual charge-pump circuit with±15-kV ESD (HBM and IEC61000-4-2, Air-Gap Discharge) and ±8-kV ESD (IEC61000-4-2, Contact Discharge)protection on serial-port connection pins. The device meets the requirements of TIA/EIA-232-F and provides theelectrical interface between an asynchronous communication controller and the serial-port connector. Thiscombination of drivers and receivers matches that needed for the typical serial port used in an IBM PC/AT, orcompatible. The charge pump and four small external capacitors allow operation from a single 3-V to 5.5-Vsupply. In addition, the device includes an always-active noninverting output (ROUT2B), which allowsapplications using the ring indicator to transmit data while the device is powered down. The device operates atdata signaling rates up to 250 kbit/s and a maximum of 30-V/ms driver output slew rate.
標簽： MULTICHANNEL 5.5 TO RS
上傳時間： 2013-10-19
上傳用戶：ddddddd
Vishay新型功率MOSFET采用反向導引TO-252DPAK封裝
上傳時間： 2013-11-09
上傳用戶：immanuel2006
The #1 Step-by-Step Guide to labviewNow Completely Updated for labview 8! Master labview 8 with the industry's friendliest, most intuitive tutorial: labview for Everyone, Third Edition. Top labview experts Jeffrey Travis and Jim Kring teach labview the easy way: through carefully explained, step-by-step examples that give you reusable code for your own projects! This brand-new Third Edition has been fully revamped and expanded to reflect new features and techniques introduced in labview 8. You'll find two new chapters, plus dozens of new topics, including Project Explorer, AutoTool, XML, event-driven programming, error handling, regular expressions, polymorphic VIs, timed structures, advanced reporting, and much more. Certified labview Developer (CLD) candidates will find callouts linking to key objectives on NI's newest exam, making this book a more valuable study tool than ever. Not just what to d why to do it! Use labview to build your own virtual workbench Master labview's foundations: wiring, creating, editing, and debugging VIs; using controls and indicators; working with data structures; and much more Learn the "art" and best practices of effective labview development NEW: Streamline development with labview Express VIs NEW: Acquire data with NI-DAQmx and the labview DAQmx VIs NEW: Discover design patterns for error handling, control structures, state machines, queued messaging, and more NEW: Create sophisticated user interfaces with tree and tab controls, drag and drop, subpanels, and more Whatever your application, whatever your role, whether you've used labview or not, labview for Everyone, Third Edition is the fastest, easiest way to get the results you're after!
上傳時間： 2013-10-14
上傳用戶：shawvi
ADS to MDK 轉換例程由西安畢博制作的MDK指導視頻，下載后打開Realview mdk1.htm頁面即可播放，內容包括：模擬仿真、開發環境的建立、啟動代碼概述等，是您盡快上手MDK的好工具
上傳時間： 2013-12-21
上傳用戶：dalidala
Abstract: Engineers often wish that radio susceptibility (RS) or radio immunity could be cured with an antibiotic, a vaccine, or someform of cure-all. Unfortunately, solving the RS problem is not that easy. Indeed, the laws of physics apply. In this article we discusssources of RS. We also offer tips and hints to protect systems, power supplies, printed circuit boards (PCBs), and electroniccomponents from radio frequency interference.
標簽： Susceptibility Radio 無線電干擾
上傳時間： 2014-12-30
上傳用戶：旗魚旗魚
