A recent trend in the design of portable devices has beento use ceramic capacitors to filter DC/DC converter inputs.Ceramic capacitors are often chosen because of theirsmall size, low equivalent series resistance (ESR) and highRMS current capability. Also, recently, designers havebeen looking to ceramic capacitors due to shortages oftantalum capacitors.
上傳時間: 2013-11-05
上傳用戶:comer1123
The LTM4600 DC/DC μModule regulator is a complete highpower density stepdown regulator for 10A continuous (14Apeak) loads. The device has two voltage options: 20VINmaximum for the LTM4600EV and 28VIN maximum for theLTM4600HVEV each housed in a small 15mm ¥ 15mm ¥2.8mm LGA surface mount package.
上傳時間: 2013-10-10
上傳用戶:adada
The LTM8020, LTM8021, LTM8022 and LTM8023 μModule®regulators are complete easy-to-use encapsulated stepdownDC/DC regulators intended to take the pain and aggravationout of implementing a switching power supplyonto a system board. With a μModule regulator, you onlyneed an input cap, output cap and one or two resistorsto complete the design. As one might imagine, this highlevel of integration greatly simplifi es the task of printedcircuit board design, reducing the effort to four categories:component footprint generation, component placement,routing the nets, and thermal vias.
上傳時間: 2014-01-18
上傳用戶:laomv123
The design of battery-powered equipment can often bequite challenging. Since few ICs can operate directly fromthe end-of-life voltage from a 2-cell battery (about 1.8V),most systems require a DC/DCconverter. The systemdesigner often has a limited area in which to place the DC/DC converter; associated inductors and capacitors must be
上傳時間: 2013-11-23
上傳用戶:wys0120
鎖定放大是微弱信號檢測的重要手段。基于相關檢測理論,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
The latest generation of Texas Instruments (TI) boardmountedpower modules utilizes a pin interconnect technologythat improves surface-mount manufacturability.These modules are produced as a double-sided surfacemount(DSSMT) subassembly, yielding a case-less constructionwith subcomponents located on both sides of theprinted circuit board (PCB). Products produced in theDSSMT outline use the latest high-efficiency topologiesand magnetic-component packaging. This providescustomers with a high-efficiency, ready-to-use switchingpower module in a compact, space-saving package. Bothnonisolated point-of-load (POL) switching regulators andthe isolated dc/dc converter modules are being producedin the DSSMT outline.TI’s plug-in power product line offers power modules inboth through-hole and surface-mount packages. The surfacemountmodules produced in the DSSMT outline use asolid copper interconnect with an integral solder ball fortheir
上傳時間: 2013-10-10
上傳用戶:1184599859
XRP7714是一款四輸出脈寬調制(PWM)分級降壓(step down)DC-DC控制器,并具有內置LDO提供待機電源。該器件在單個IC上為電池供電的產品提供了整套的電源管理方案,并且通過內含的I2C串行接口進行整體的編程配置。XRP7714器件的每一路輸出電壓的編程范圍是0.9V~5.1V,此范圍內無需外部分壓器。可編程DPWM開關頻率的范圍從300kHz到1.5MHz,使用戶能夠在效率和元件大小之間取得最優方案。為了讓用戶能夠在設計的多路電源XRP7714系統能夠取得最優的方案,下文將詳細的介紹影響XRP7714系統效率的參數設置以及外圍器件的選型。
上傳時間: 2013-10-31
上傳用戶:chendawei
簡介采用模數轉換器(ADC)的現代電子系統要求更低功耗和更高性能。本文描述了采用線性電源和開關電源之間的差異,并論證了將高效DC-DC轉換器和高性能模數轉換器組合使用,可以顯著降低系統功耗,同時不降低模數轉換器的性能。
上傳時間: 2013-10-27
上傳用戶:哈哈hah
加利福尼亞州米爾皮塔斯 (MILPITAS, CA) – 2009 年 8 月 31 日 – 凌力爾特公司 (Linear Technology Corporation) 推出隔離式 RS485 微型模塊 (uModule®) 收發器 LTM2881,該器件針對大的地至地差分電壓和共模瞬變提供了保護作用。在實際的 RS485系統中,各節點之間的地電位差異很大,常常超出可容許范圍,這有可能導致通信中斷或收發器受損。LTM2881 運用內部感應信號隔離來對邏輯電平接口和線路收發器實施隔離,以中斷接地環路,從而實現了大得多的共模電壓范圍和 >30kV/μs 的卓越共模抑制性能。一個低 EMI DC-DC 轉換器負責向收發器供電,并提供了一個用于給任何外部支持元件供電的 5V 隔離電源輸出。憑借 2,500VRMS 的電流隔離、板上輔助電源和一個完全符合標準的 RS485 發送器和接收器,LTM2881 不需要使用外部元件,從而確保了一款適合隔離串行數據通信的完整、小型μModule 解決方案。
上傳時間: 2013-10-25
上傳用戶:ljj722
典型性能外型尺寸:70×62×23.5(mm)寬輸入電壓范圍,單、雙、叁路輸出典型效率(5V)80%100KHz開關頻率PCB板上式安裝
上傳時間: 2014-04-17
上傳用戶:qimingxing130