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
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
We would like to welcome you as a user of the Allegro CX, a rugged, handheld fi eld PC for data collection. Developed with the input of data collection professionals worldwide, the Allegro CX is adaptable and versatile for use in a wide variety of data collection environments. The Allegro CX continues to utilize our ergonomic, lightweight design that is standard in our line of Allegro Field PCs. This design makes your Allegro easy to use for extended periods while moving to and from data collection sites in the fi eld.
上传时间： 2015-01-02
上传用户：zhangyi99104144
This article discusses some issues that a typical Windows C++ programmer will encounter when approaching Symbian OS for the first time. Our experience in developing for three successive versions of Symbian OS has given us considerable perspective on what can be difficult when working in this otherwise rich and stable environment. While one reason for Symbian s success may be the desire of many mobile phone manufacturers not to be tied to Microsoft, the other reason is that Symbian has put together a lightweight, elegant system that succeeds in providing a very impressive range of functionality. Here are some pointers to help ease the transition to successful Symbian OS application development.
标签： programmer discusses encounter article
上传时间： 2017-07-30
上传用户：zhaiyanzhong
lwip是一个轻量级的TCP/IP协议栈（lightweight TCP/IP Stack）实现，最初是瑞士计算机科学学院Adam Dunkels编写的一个应用于无操作系统的嵌入式系统中的TCP/IP协议栈，后来作为一个开源（open source）项目，由一个全球性的团队进行开发和维护。
上传时间： 2016-06-13
上传用户：tttm1030
VIP专区-嵌入式/单片机编程源码精选合集系列（74）资源包含以下内容：1. Using lightweight IP with the Nios II Processor_nios2_lwip_tutorial,This tutorial familiarizes you w.2. 包含了CS8900的接口原理图.3. NE2000兼容网卡驱动编写指南.4. ARM开发流程 ppt文档.5. ping指令详解, c语言编写.6. NIOS II UART 测试程序.7. NIOS II 与USB接口的程序.8. AD9852 串行控制子程序.9. 可以测量马达的实际转速,用的IC 是AT89C2051,也可以用于AT89C51.10. Keil工具Hello word源码.11. LCD1601的液晶程序.12. LCD1602的程序.13. 电话远程控制的想法已有一段是时间.14. 这是一个小时计的程序.15. SONY的液晶驱动程序,包括音量,亮度的调整,值得参考一下..16. CPLD在DS—FH混合扩频通信系统中的应用.17. 基于LPC2131的SPI编程驱动,主机方式,查询方式.18. pwm电机步进控制.19. SL811 USB 开发代码.20. 基于UCM40的超声波测距函数,可测0.08---2.5米距离,数值精确.21. S3C2440开发板原理图.22. EVMDM642开发板的详细硬件介绍及原理图。PDF格式。.23. 经典的dds发生器ad9851vhdl的并行通信代码.24. mpc2872系列的usb controller产生sof源码.25. TI 的TMS320F2812芯片的开发板原理图和说明.26. 一份基于AT89C51SND1A控制的MP3原理图.27. 基于三星S3C2410 ARM芯片的开发板原理图.28. EVB使用CreateProcess API 呼叫IE 撥放wma 範例.29. FlashROM的存储控件操作源代码.30. 键盘Key滤波功能源代码.31. altera的usb下载线的制作资料.32. 嵌入式系统中,从任意一点到任意一点画直线算法程序.33. 本程序是用VHDL语言实现对AD控制.34. 该程序应用轮换查询的方式实现了键盘的扫描.35. 该程序为niosＩＩ环境下的１３０２编程可以直接应用.36. TMS320F2812原理图设计,不是很完善。希望高人指点。.37. Mega16微打驱动.38. ACN协议 Artnet协议 DMX512-A 调光网络.39. NIOSII 实验指导.40. xilinx 开发板原理图,里面含有pcb图,自己完全可以做一块来玩,不用买别人的,很省钱,又锻炼了自己..
上传时间： 2013-06-17
上传用户：eeworm
