A light-emitting diode (LED) is a semiconductor deviCE that emits narrow-spectrum incoherent light when forward-biased.The color of the emitted light depends on the chemical composition of the semiconductor material used, and can benear-ultraviolet, visible or infrared. LEDs are more prevalent today than ever before, replacing traditional incandescent andfluorescent bulbs in many lighting applications. Incandescents use a heated filament, are subject to breakage and burnoutand operate at a luminous efficiency of 2% to 4%. Fluorescents are more efficient, at 7% to 12%, but require highdrive voltage and contain mercury, a toxic substance that may be eventually banned in certain countries. LEDs, however,produce light directly through electroluminescence, operate at low voltage and can deliver over 20% luminous efficiency.
上传时间： 2013-11-07
上传用户：xiaoyuer
The CN3052A is a complete constant-current /constant voltage linear charger for single cell Li-ion and Li Polymer rechargeable batteries. The deviCE contains an on-chip power MOSFET and eliminates the need for the external sense resistor and blocking diode.
上传时间： 2013-11-10
上传用户：子虚乌有
VCC:C=circuit 表示电路的意思, 即接入电路的电压; VDD:D=deviCE 表示器件的意思, 即器件内部的工作电压; VSS:S=series 表示公共连接的意思,通常指电路公共接地端电压.
标签： VCC_VDD_VSS
上传时间： 2013-11-22
上传用户：squershop
PCI ExpressTM is the third generation of PCI (PeripheralComponent Interconnect) technology used to connect I/Operhipheral deviCEs in computer systems. It is intended asa general purpose I/O deviCE interconnect that meets theneeds of a wide variety of computing platforms such asdesktop, mobile, server and communications. It alsospecifies the electrical and mechanical attributes of thebackplane, connectors and removable cards in thesesystems.
上传时间： 2013-11-17
上传用户：squershop
To this day, Power over Ethernet (PoE) continues to gainpopularity in today’s networking world. The 12.95Wdelivered to the Powered deviCE (PD) input supplied bythe Power Sourcing Equipment (PSE) is a universal supply.Each PD provides its own DC/DC conversion from anominal 48V supply, thus eliminating the need for a correctvoltage wall adapter. However, higher power deviCEscan not take advantage of standard PoE because of itspower limitations, and must rely on a large wall adapteras their primary supply. The new LTC4268-1 breaks thispower barrier by allowing for power of up to 35W for suchpower-hungry 2-pair PoE applications. The LTC4268-1provides a complete solution by integrating a high powerPD interface control with an isolated fl yback controller.
上传时间： 2014-12-24
上传用户：jasson5678
Handheld designers often grapple with ways to de-bounceand control the on/off pushbutton of portable deviCEs.Traditional de-bounce designs use discrete logic, fl ipflops, resistors and capacitors. Other designs includean onboard microprocessor and discrete comparatorswhich continuously consume battery power. For highvoltage multicell battery applications, a high voltageLDO is needed to drive the low voltage deviCEs. All thisextra circuitry not only increases required board spaceand design complexity, but also drains the battery whenthe handheld deviCE is turned off. Linear Technology addressesthis pushbutton interface challenge with a pairof tiny pushbutton controllers.
上传时间： 2013-11-18
上传用户：ZJX5201314
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.
上传时间： 2013-10-22
上传用户：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.
上传时间： 2013-10-21
上传用户：非衣2016
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.
上传时间： 2013-12-20
上传用户：ABCDE
The LTM4601 DC/DC μModule regulator is a completehigh power density stepdown regulator for up to 12Acontinuous (14A peak) loads. The deviCE is housed ina small 15mm ¥ 15mm ¥ 2.8mm LGA surface mountpackage, thus the large power dissipation is a challengein some applications. This thermal application note willprovide guidelines for using the μModule regulator inambient environments with or without air fl ow. Loadcurrent derating curves are provided for several inputvoltages and output voltages versus ambient temperatureand air fl ow.
上传时间： 2013-10-19
上传用户：bakdesec
