The LTC®4099 high effi ciency USB power manager andLi-Ion/Polymer battery charger seamlessly managespower distribution from multiple sources in portableapplications. It is differentiated from other USB powermanagers by its bidirectional I2C port that allows the hostmicroprocessor to control and monitor all aspects of theUSB power management and battery charging processes.In addition, a programmable interrupt generation functionalerts the host microprocessor to changes in device statusand provides unprecedented control of power managementfunctions. This high degree of confi gurability allowspost-layout changes in operation, even changes in thefi eld, and it allows a single qualifi ed device to be usedin a variety of products, thus reducing design time andeasing inventory management.
上傳時(shí)間： 2013-10-22
上傳用戶：18602424091
An essential component of a noise-free audio device isa clean power supply, but few switching regulators canoperate at high efficiency while keeping the switchingfrequency out of the audio band. The LTC®3620 fills thisvoid. It is a high efficiency 15mA buck regulator with aprogrammable minimum switching frequency, making itpossible to virtually eliminate audible switching noise. Theinternal synchronous switches and low quiescent currentof this buck regulator provide the ability to maintain highefficiency, while its small footprint makes it ideal for tiny,low power audio applications.
標(biāo)簽： 超低功率 控制 開(kāi)關(guān)噪聲 方案
上傳時(shí)間： 2013-10-21
上傳用戶：非衣2016
What would happen if someone connected 24V to your12V circuits? If the power and ground lines were inadvertentlyreversed, would the circuits survive? Does yourapplication reside in a harsh environment, where the inputsupply can ring very high or even below ground? Evenif these events are unlikely, it only takes one to destroya circuit board.
標(biāo)簽： 敏感電路 保護(hù) 過(guò)壓 電源反接
上傳時(shí)間： 2013-10-26
上傳用戶：jackandlee
In a recent discussion with a system designer, the requirementfor his power supply was to regulate 1.5Vand deliver up to 40A of current to a load that consistedof four FPGAs. This is up to 60W of power that must bedelivered in a small area with the lowest height profi lepossible to allow a steady fl ow of air for cooling. Thepower supply had to be surface mountable and operateat high enough effi ciency to minimize heat dissipation.He also demanded the simplest possible solution so histime could be dedicated to the more complex tasks. Asidefrom precise electrical performance, this solution had toremovethe heat generated during DC to DC conversionquickly so that the circuit and the ICs in the vicinity do notoverheat. Such a solution requires an innovative designto meet these criteria:
標(biāo)簽： FPGA DCDC 集成 穩(wěn)壓器
上傳時(shí)間： 2013-11-24
上傳用戶：defghi010
Telecommunication, satellite links and set-top boxes allrequire tuning a high frequency oscillator. The actualtuning element is a varactor diode, a 2-terminal device thatchanges capacitance as a function of reverse bias voltage.1 The oscillator is part of a frequency synthesizingloop, as detailed in Figure 1. A phase locked loop (PLL)compares a divided down representation of the oscillatorwith a frequency reference. The PLL’s output is levelshifted to provide the high voltage necessary to bias thevaractor, which closes a feedback loop by voltage tuningthe oscillator. This loop forces the voltage controlledoscillator (VCO) to operate at a frequency determined bythe frequency reference and the divider’s division ratio.
標(biāo)簽： 開(kāi)關(guān)穩(wěn)壓器 低噪聲 上傳時(shí)間： 2013-12-20
上傳用戶：ABCDE
As logic systems get larger and more complex, theirsupply current requirements continue to rise. Systemsrequiring 100A are fairly common. A high current powersupply to meet such requirements usually requires parallelingseveral power regulators to alleviate the thermalstress on the individual power components. A powersupply designer is left with the choice of how to drive theseparalleled regulators: brute-force single-phase or smartPolyPhaseTM.
標(biāo)簽： 高效率 密度 多相轉(zhuǎn)換器 高電流
上傳時(shí)間： 2013-10-08
上傳用戶：zhqzal1014
Photomultipliers (PMT), avalanche photodiodes (APD),ultrasonic transducers, capacitance microphones, radiationdetectors and similar devices require high voltage,low current bias. Additionally, the high voltage must bepristinely free of noise; well under a millivolt is a commonrequirement with a few hundred microvolts sometimesnecessary. Normally, switching regulator confi gurationscannot achieve this performance level without employingspecial techniques. One aid to achieving low noise is thatload currents rarely exceed 5mA. This freedom permitsoutput fi ltering methods that are usually impractical
標(biāo)簽： DCDC 高電壓 低噪音 轉(zhuǎn)換器
上傳時(shí)間： 2013-10-28
上傳用戶：lhw888
This ink marks LTC’s eighth circuit collection publication.1We are continually surprised, to the point of near mystification, by these circuit amalgams seemingly limitlessappeal. Reader requests ascend rapidly upon publication,remaining high for years, even decades. All LTC circuitcollections, despite diverse content, share this popularity,although just why remains an open question. Why isit? Perhaps the form; compact, complete, succinct andinsular. Perhaps the freedom of selection without commitment,akin to window shopping.
標(biāo)簽： 電源轉(zhuǎn)換 測(cè)量 脈沖電路
上傳時(shí)間： 2014-01-06
上傳用戶：ligi201200
Notebook and palmtop systems need a multiplicity ofregulated voltages developed from a single battery. Smallsize, light weight, and high efficiency are mandatory forcompetitive solutions in this area. Small increases inefficiency extend battery life, making the final productmuch more usable with no increase in weight. Additionally,high efficiency minimizes the heat sinks needed onthe power regulating components, further reducing systemweight and size.
標(biāo)簽： 筆記本電腦 功率調(diào)節(jié)
上傳時(shí)間： 2013-11-11
上傳用戶：大三三
The above title is not happenstance and was arrived at afterconsiderable deliberation. As a linear IC manufacturer, it isour goal to encourage users to design and build switchingregulators. A problem is that while everyone agrees thatworking switching regulators are a good thing, everyonealso agrees that they are difficult to get working. Switchingregulators, with their high efficiency and small size, areincreasingly desirable as overall package sizes shrink.Unfortunately, switching regulators are also one of themost difficult linear circuits to design. Mysterious modes,sudden, seemingly inexplicable failures, peculiar regulationcharacteristics and just plain explosions are commonoccurrences. Diodes conduct the wrong way. Things gethot that shouldn’t. Capacitors act like resistors, fusesdon’t blow and transistors do. The output is at ground, andthe ground terminal shows volts of noise.
標(biāo)簽： Regulators Switching Poets for
上傳時(shí)間： 2013-12-19
上傳用戶：奇奇奔奔
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