General Description The LM621 is a bipolar IC designed for commutation of brushless DC motors. The part is compatible with both three- and four-phase motors. It can directly drive the power switching devices used to drive the motor. The LM621 provides an adjustable dead-time circuit to eliminate ``shootthrough'' current spiking in the power switching circuitry. Operation is from a 5V supply, but output swings of up to 40V are accommodated. The part is packaged in an 18-pin, dual-in-line package.
上傳時間: 2013-07-24
上傳用戶:sdq_123
·詳細說明:DVB MHP 標準(英文版)以及 mpeg2 標準(中、英文版)-DVB MHP standard (English version) as well as mpeg2 standard (center, English version) 文件列表: DVB-MHP-spec.pdf IS138181.DOC MPEG2-0.DOC
上傳時間: 2013-04-24
上傳用戶:sevenbestfei
·Stanford&IBM牛人經典之作 - Digital Control of Dynamic SystemsEditorial ReviewsProduct DescriptionThis well-respected, market-leading text discusses the use of digital computers in the real-time co
標簽: nbsp Hardcover Digital Control
上傳時間: 2013-07-31
上傳用戶:cuiyashuo
Cadence.zip是著名的pcb制作及仿真軟件,比起altium designed winter2009功能更強,布線功能更完全
上傳時間: 2013-09-06
上傳用戶:dsgkjgkjg
Abstract: This document explains how the Cupertino (MAXREFDES5#) subsystem reference design meets the higher resolution, higher voltage,and isolation needs of industrial control and industrial automation applications. Hardware and firmware design files as well as FFTs andhistograms from lab measurements are provided.
上傳時間: 2013-10-21
上傳用戶:mnacyf
微弱信號檢測裝置 四川理工學院 劉鵬飛、梁天德、曾學明 摘要: 本設計以TI的Launch Pad為核心板,采用鎖相放大技術設計并制作了一套微弱信號檢測裝置,用以檢測在強噪聲背景下已知頻率微弱正弦波信號的幅度值,并在液晶屏上數字顯示出所測信號相應的幅度值。實驗結果顯示其抗干擾能力強,測量精度高。 關鍵詞:強噪聲;微弱信號;鎖相放大;Launch Pad Abstract: This design is based on the Launch Pad of TI core board, using a lock-in amplifier technique designed and produced a weak signal detection device, to measure the known frequency sine wave signal amplitude values of the weak in the high noise background, and shows the measured signal amplitude of the corresponding value in the liquid crystal screen. Test results showed that it has high accuracy and strong anti-jamming capability. Keywords: weak signal detection; lock-in-amplifier; Launch Pad 1、引言 隨著現代科學技術的發展,在科研與生產過程中人們越來越需要從復雜高強度的噪聲中檢測出有用的微弱信號,因此對微弱信號的檢測成為當前科研的熱點。微弱信號并不意味著信號幅度小,而是指被噪聲淹沒的信號,“微弱”也僅是相對于噪聲而言的。只有在有效抑制噪聲的條件下有選擇的放大微弱信號的幅度,才能提取出有用信號。微弱信號檢測技術的應用相當廣泛,在生物醫學、光學、電學、材料科學等相關領域顯得愈發重要。 2、方案論證 針對微弱信號的檢測的方法有很多,比如濾波法、取樣積分器、鎖相放大器等。下面就針對這幾種方法做一簡要說明。 方案一:濾波法。 在大部分的檢測儀器中都要用到濾波方法對模擬信號進行一定的處理,例如隔離直流分量,改善信號波形,防止離散化時的波形混疊,克服噪聲的不利影響,提高信噪比等。常用的噪聲濾波器有:帶通、帶阻、高通、低通等。但是濾波方法檢測信號不能用于信號頻譜與噪聲頻譜重疊的情況,有其局限性。雖然可以對濾波器的通頻帶進行調節,但其噪聲抑制能力有限,同時其準確性與穩定性將大打折扣。
上傳時間: 2013-11-04
上傳用戶:lty6899826
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
Recently a new technology for high voltage Power MOSFETshas been introduced – the CoolMOS™ . Based on thenew device concept of charge compensation the RDS(on) areaproduct for e.g. 600V transistors has been reduced by afactor of 5. The devices show no bipolar current contributionlike the well known tail current observed during the turn-offphase of IGBTs. CoolMOS™ virtually combines the lowswitching losses of a MOSFET with the on-state losses of anIGBT.
標簽: COOLMOS
上傳時間: 2013-11-14
上傳用戶:zhyiroy
A MEMS microphone IC is unique among Analog Devices, Inc., products in that its input is an acoustic pressure wave. For this reason, some specifications included in the data sheets for these parts may not be familiar, or familiar specifications may be applied in unfamiliar ways. This application note explains the specifica-tions and terms found in MEMS microphone data sheets so that the microphone can be appropriately designed into a system.
上傳時間: 2013-10-31
上傳用戶:masochism
Abstract: It is incredible how many programmable logic controls (PLCs) around us make our modern life possible and pleasant.Machines in our homes heat and cool our air and water, as well as preserve and cook our food. This tutorial explains the importanceof PLCs, and describes how to choose component parts using the parametric tools on the Maxim's website.A similar version of this article was published February 29, 2012 in John Day's Automotive Electronic News.
上傳時間: 2013-11-10
上傳用戶:liaocs77