Demonstration Circuits
上传时间： 2013-11-08
上传用户：电子世界
手机已成为人们生活中不可缺少的通信工具。目前手机都是由可充电的锂离子电池供电，在野外或无市电的情况下，手机随时可能没电，这给使用者带来许多不便。经研究人体与环境之间总是存在温差，利用温差电技术可实现真正意义上的手机永不断电。温差电技术是绿色环保的发电技术，是一种新的能源替换方式，可将低品位热源的热量有效地转化为电能，同时减少能量消耗，缓解环境污染问题。因此，微型温差电器件将有美好的应用前景，手机体温充电系统对于新能源开发必定具有重要的实际意义。
上传时间： 2013-10-21
上传用户：lchjng
牵涉到开关电源技术设计或分析成为电子工程师的心头之痛已是不争的事实。随着集成化，微型化成为未来设计主流，电子产品设计安全设计要求的快速提高，设计安全、高效的开关电源相关产品设计成为电源工程师的首要任务，为了帮助工程师解决这方面的难题，电子发烧友网整合设计资源特别推出《开关电源设计指南——基础篇》电子书（ 免费在线下载数字版《开关电源设计指南——基础篇》 ），本电子书论述了开关电源最常用拓扑的基本原理、磁性元件的设计原则及闭环反馈稳定性和驱动保护、电磁兼容性分析等相关内容。开关电源设计指南——基础篇旨在解决工程师日常设计难题所需的基础知识，希望这本电子书和以前推出的电子书一样可以帮助本土工程师的设计创新。
上传时间： 2013-11-11
上传用户：zgz317
Advancements in board assembly, PCB layout anddigital IC integration have produced a new generationof densely populated, high performance systems. Theboard-mounted point-of-load (POL) DC/DC power suppliesin these systems are subject to the same demandingsize, high power and performance requirements asother subsystems. The rigorous new POL demands aredifficult to meet with traditional controller or regulatorICs, or power modules.
上传时间： 2014-12-24
上传用户：lbbyxmraon
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
Alkaline batteries are convenient because they’re easy tofi nd and relatively inexpensive, making them the powersource of choice for portable instruments and devicesused for outdoor recreation. Their long shelf life alsomakes them an excellent choice for emergency equipmentthat may see infrequent use but must be ready to go on amoment’s notice. It is important that the DC/DC convertersin portable devices operate over the widest possiblebattery voltage range to extend battery run time, and thussave the user from frequent battery replacement.
上传时间： 2014-12-24
上传用户：569342831
Once relegated to the hinterlands of low cost indicatorlights, the LED is again in the spotlight of the lightingworld. LED lighting is now ubiquitous, from car headlightsto USB-powered lava lamps. Car headlights exemplifyapplications that capitalize on the LED’s clear advantages—unwavering high quality light output, tough-assteelrobustness, inherent high effi ciency—while a USBlava lamp exemplifi es applications where only LEDs work.Despite these clear advantages, their requirement forregulated voltage and current make LED driver circuitsmore complex than the venerable light bulb, but some newdevices are closing the gap. For instance, the LTM®8040μModule™ LED driver integrates all the driver circuitryinto a single package, allowing designers to refocus theirtime and effort on the details of lighting design criticalto a product’s success.
上传时间： 2013-10-16
上传用户：togetsomething
随着消费者购买便携设备数量的增多，他们也被具有各种非标准连接器的诸多电源适配器所束缚。为了解决这一问题，微型USB接口成为电池充电和数据传输的标准。MAX14578AE/MAX14578E过压保护充电检测器和限流开关大大简化了微型USB端口的设计，从而使终端用户操作更加轻松
上传时间： 2013-10-09
上传用户：chukeey
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
