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
This document presents design techniques and reference circuits thAT power Virtex™-4 FXRocketIO™ multi-gigabit transceivers (MGTs) operATing AT dATa rATes below 3.125 Gb/s.When using multiple transceivers, it is sometimes preferred to power them from a switchingpower supply. However, switching power supplies generATe noise thAT affects transceiver
上传时间： 2013-11-18
上传用户：huang111
Traditionally, an Electronic Circuit Breaker (ECB) comprisesa MOSFET, a MOSFET controller and a current senseresistor. The LTC®4213 does away with the sense resistorby using the RDS(ON) of the external MOSFET. The resultis a simple, small solution thAT offers a signifi cant lowinsertion loss advantage AT low operATing load voltage.The LTC4213 feATures two circuit breaking responses tovarying overload conditions with three selectable tripthresholds and a high side drive for an external N-channelMOSFET switch.
上传时间： 2014-03-02
上传用户：lixinxiang
Video cable driver amplifi er output stages traditionallyrequire a supply voltage of AT least 6V in order to providethe required output swing. This requirement is usuallymet with 5V supplies by adding a boost regulATor or asmall local negATive rail, say via the popular LT®1983-3.Such additional circuitry is unnecessary in typical 1VP-Pvideo connections, such as HD component video, if thecable driver amplifi ers simply offer near rail-to-rail outputcapability when powered from 5V.
上传时间： 2013-11-16
上传用户：yanyangtian
Automotive bATteries, industrial power supplies, distributedsupplies and wall transformers are all sources ofwide-ranging high voltage inputs. The easiest way to stepdown these sources is with a high voltage monolithicstep-down regulATor thAT can directly accept a wide inputrange and produce a well-regulATed output. The LT®3493accepts inputs from 3.6V to 36V and LT3481 acceptsinputs from 3.6V to 34V. Both provide excellent lineand load regulATion and dynamic response. The LT3481offers a high effi ciency solution over a wide load range andkeeps the output ripple low during Burst Mode® operATionwhile the LT3493 provides a tiny solution with minimalexternal components. The LT3493 operATes AT 750kHzand the LT3481 has adjustable frequency from 300kHzto 2.8MHz. High frequency operATion enables the use ofsmall, low cost inductors and ceramic capacitors.
上传时间： 2014-12-24
上传用户：Pzj
Piezoelectric motors are used in digital cameras for autofocus,zooming and optical image stabilizATion. Theyare relATively small, lightweight and effi cient, but theyalso require a complicATed driving scheme. Traditionally,this challenge has been met with the use ofseparATecircuits, including a step-up converter and an oversizedgeneric full-bridge drive IC. The resulting high componentcount and large board space are especially problemATicin the design of cameras for ever shrinking cell phones.The LT®3572 solves these problems by combining astep-up regulATor and a dual full-bridge driver in a 4mm× 4mm QFN package. Figure 1 shows a typical LT3572Piezo motor drive circuit. A step-up converter is usedto generATe 30V from a low voltage power source suchas a Li-Ion bATtery or any input power source within thepart’s wide input voltage range of 2.7V to 10V. The highoutput voltage of the step-up converter, adjustable upto 40V, is available for the drivers AT the VOUT pin. Thedrivers operATe in a full-bridge fashion, where the OUTAand OUTB pins are the same polarity as the PWMA andPWMB pins, respectively, and the OUTA and OUTB pinsare inverted from PWMA and PWMB, respectively. Thestep-up converter and both Piezo drivers have their ownshutdown control. Figure 2 shows a typical layout
上传时间： 2013-11-18
上传用户：hulee
The LTC®3610 is a high power monolithic synchronousstep-down DC/DC regulATor thAT can deliver up to 12Aof continuous output current from a 4V to 24V (28Vmaximum) input supply. It is a member of a high currentmonolithic regulATor family (see Table 1) thAT feATuresintegrATed low RDS(ON) N-channel top and bottomMOSFETs. This results in a high effi ciency and highpower density solution with few external components.This regulATor family uses a constant on-time valleycurrent mode architecture thAT is capable of operATingAT very low duty cycles AT high frequency and with veryfast transient response. All are available in low profi le(0.9mm max) QFN packages.
上传时间： 2013-11-07
上传用户：moerwang
Today’s computer, dATacom, and telecom systems demandpower supplies thAT are effi cient, respond quicklyto load transients and accurATely regulATe the voltageAT the load. For example, load current can be measuredby using the inductor DCR, thus eliminATing the needfor a dedicATed sense resistor. Inductor DCR sensingincreases effi ciency—especially AT heavy load—whilereducing component cost and required board space.The LTC®3856 single-output 2-phase synchronous buckcontroller improves the accuracy of inductor DCR sensingby compensATing for changes in DCR due to temperATure.
上传时间： 2013-11-05
上传用户：guobing703
Handheld electronic devices play a key role in our everydaylives. Because dependability is paramount, handhelds arecarefully engineered with lightweight power sources forreliable use under normal conditions. But no amount ofcareful engineering can prevent the mistreATment theywill undergo AT the hands of humans. For example, whAThappens when a factory worker drops a bar code scanner,causing the bATtery to pop out? Such events areelectronically unpredictable, and important dATa storedin volATile memory would be lost without some form ofsafety net—namely a short-term power holdup systemthAT stores suffi cient energy to supply standby power untilthe bATtery can be replaced or the dATa can be stored inpermanent memory.
上传时间： 2013-11-05
上传用户：coeus
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
