Abstract: Rail splitting is creating an artificial virtual ground as a reference voltage. It is used to set the signalto match the op amp's "sweet spot." An op amp has the most linear- and distortion-free qualities at that sweetspot. Typically, the sweet spot occurs near the center between the single power rail and ground. In the case ofa number of signals, the virtual ground can control channel DC errors when multiplexing or switching thesignals.
上传时间： 2013-10-23
上传用户：wushengwu
Linear Technology offers a variety of devices that simplifyconverting power from a USB cable, but the LTC®3455represents the highest level of functional integration yet. The LTC3455 seamlessly manages power flowbetween an AC adapter, USB cable and Li-ion battery,while complying with USB power standards, all from a4mm × 4mm QFN package. In addtion, two high efficiencysynchronous buck converters generate low voltage railswhich most USB-powered peripherals require. TheLTC3455 also provides power-on reset signals for themicroprocessor, a Hot SwapTM output for poweringmemory cards as well as an uncommitted gain blocksuitable for use as a low-battery comparator or an LDOcontroller. The PCB real estate required for the entire USBpower control circuit and two DC/DC converters is only225mm2.
上传时间： 2013-11-02
上传用户：名爵少年
Speed and accuracy don’t always go hand-in-handin DC/DC converter systems—that is, until now. TheLTC3811 is a dual output, fi xed frequency current modeDC/DC switching regulator controller designed for one oftoday’s most demanding power supply applications: highcurrent, low voltage processor core supplies.
上传时间： 2013-11-20
上传用户：aix008
Industrial remote monitoring systems and keep-alivecircuits spend most of their time in standby mode. Manyof these systems also depend on battery power, so powersupply effi ciency in standby state is very important tomaximize battery life. The LT®8410/-1 high effi ciencyboost converter is ideal for these systems, requiringonly 8.5μA of quiescent current in standby mode. Thedevice integrates high value (12.4M/0.4M) output feedbackresistors, signifi cantly reducing input current whenthe output is in regulation with no load. Other featuresinclude an integrated 40V switch and Schottky diode,output disconnect with current limit, built in soft-start,overvoltage protection and a wide input range, all in atiny 8-pin 2mm × 2mm DFN package.
上传时间： 2013-11-22
上传用户：新手无忧
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.
上传时间： 2013-10-09
上传用户：Jerry_Chow
Specifying the right reference and applying it correctly isa more difficult task than one might first surmise, consideringthat references are only 2- or 3-terminal devices.Although the word “accuracy” is most often spoken inreference to references, it is dangerous to use this wordtoo freely because it can mean different things to differentpeople. Even more perplexing is the fact that a referenceclassified as a dog in one application is a panacea inanother. This application note will familiarize the readerwith the various aspects of reference “accuracy” andpresent some tips on extracting maximum performancefrom any reference.
标签： 电压基准
上传时间： 2013-10-14
上传用户：liuwei6419
This collection of circuits was worked out between June1991 and July of 1994. most were designed at customerrequest or are derivatives of such efforts. All representsubstantial effort and, as such, are disseminated here forwider study and (hopefully) use.1 The examples areroughly arranged in categories including power conversion,transducer signal conditioning, amplifiers and signalgenerators. As always, reader comment and questionsconcerning variants of the circuits shown may be addresseddirectly to the author.
上传时间： 2013-11-15
上传用户：凌云御清风
most portable computers have built-in sockets to acceptsmall PC cards for use as extended memories, fax modems,network interfaces, wireless communicators and awide assortment of other functions. The Personal ComputerMemory Card International Association (PCMCIA)has released specifications that outline the general powerrequirements for these cards.
上传时间： 2013-11-18
上传用户：bcjtao
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
上传时间： 2013-11-23
上传用户：wys0120
现代车辆网络结构明显变得更加复杂了。除了传统的CAN和LIN总线系统外，视频和多媒体系统的传输也促使高带宽网络，如most、 FlexRay及以太网等的需求。汽车OEM越来越关心网络维护及软件的复杂性。此次会议将探讨各种汽车网络架构及飞思卡尔Qorivva 32位MCU产品系列如何帮助OEM应对这些挑战。
上传时间： 2013-11-15
上传用户：Aeray
