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TOP-Down

自顶向下(TOP-Down)的分析算法通过在最左推导中描述出各个步骤来分析记号串输入。将大型的数字电路设计分割成大小不一的小模块来实现特定的功能,最后通过由顶层模块调用子模块来实现整体功能,这就是TOP-Down的设计思想。
  • DN442 I2C可控降压紧凑型同步DC/DC稳压器

      The LTC®3562 quad output step-down regulator is designedfor multicore handheld microprocessor applications thatoperate from a single Li-Ion battery. Its four monolithic, higheffi ciency buck regulators support Intel’s mobile CPU P-Stateand C-State energy saving operating modes. The outputvoltages are independently controllable via I2C, and eachoutput can be independently started and shut down. Designerscan choose from power saving pulse-skipping mode orBurst Mode® operation, or select low noise LDO mode. Thespace-saving LTC3562 is available in a 3mm × 3mm QFNpackage and requires few external components.

    标签: DC 442 I2C DN

    上传时间: 2013-10-07

    上传用户:1583060504

  • DN458降压转换器简化低电压设计

      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.

    标签: 458 DN 降压转换器 低电压

    上传时间: 2013-10-09

    上传用户:Jerry_Chow

  • 如何制作使用μModule降压稳压器的输入输出电压

      Linear Technology’s DC/DC step-down μModule®regulators are complete switchmode power supplies in asurface-mount package. They include the DC/DC controller,inductor, power switches and supporting circuitry.These highly integrated regulators also provide an easysolution for applications that require negative outputvoltages. In other words, these products can operate asinverting buck-boost regulators. As a result, the lowestpotential in the circuit is not the standard 0V, but –VOUT,which must be tied to the μModule regulator’s GND. Allsignals are now referred to –VOUT.

    标签: Module 如何制作 降压稳压器 输入输出

    上传时间: 2013-10-22

    上传用户:ztj182002

  • 高集成驱动器满足新一代智能手机

      Abstract: This article discusses future trends in the design of smartphones and other consumer products. The discussion focuses onthe importance of integration, which saves valuable PCB space and drives down costs.

    标签: 集成 智能手机 驱动器

    上传时间: 2014-01-13

    上传用户:lhw888

  • 多路电源XRP7714参数设置及外围器件的选择

    XRP7714是一款四输出脉宽调制(PWM)分级降压(step down)DC-DC控制器,并具有内置LDO提供待机电源。该器件在单个IC上为电池供电的产品提供了整套的电源管理方案,并且通过内含的I2C串行接口进行整体的编程配置。XRP7714器件的每一路输出电压的编程范围是0.9V~5.1V,此范围内无需外部分压器。可编程DPWM开关频率的范围从300kHz到1.5MHz,使用户能够在效率和元件大小之间取得最优方案。为了让用户能够在设计的多路电源XRP7714系统能够取得最优的方案,下文将详细的介绍影响XRP7714系统效率的参数设置以及外围器件的选型。

    标签: 7714 XRP 多路电源 参数

    上传时间: 2013-10-31

    上传用户:chendawei

  • 2.4GHz PTR4000无线嵌入式模块高速率1Mbps、

    产品特性2.4Ghz全球开放ISM频段,免许可证使用最高工作速率1Mbps,高效GMSK调制,抗干扰能力强,特别适合工业控制场合125频道,满足多点通信和跳频通信需要内置硬件CRC检错和点对多点通信地址控制低功耗1.9~3.6V工作Power Down模式下状态仅为1uA内置2.4Ghz天线,体积小巧约24x24mm不包括天线模块可软件设地址,只有收到本机地址时才会输出数据(提供中断指示,可直接接各种单片机使用,软件编程非常方便内置专门稳压电路,使用各种电源包括DC/DC开关电源均有很好的通信效果标准DIP间距接口便于嵌入式应用PTR4000-Quick-DEV快速开发系统,含开发板、源代码、原理图等详细资料,即开即用,上手快,缩短您的开发时间

    标签: 1Mbps 4000 2.4 GHz

    上传时间: 2013-10-12

    上传用户:sz_hjbf

  • 基于AT89C52单片机的温度巡回检测系统设计

    阐述了一个由上位PC机和AT89C52下位单片机组成的主从分布式温度巡回检测系统。主从机采用RS-485 串行通讯标准进行通信,可在下位单片机实现基本的温度数据巡回检测基础上,由上位PC机实现综合处理功能或扩展为远程操作。整个系统具有巡检速度快,扩展性好的特点。 Abstract:  In this paper,a top PC and AT89C52 under-bit microcontrollers from the main component of the tour distributed temperature detection system is presented. Master and slave can use RS-485 serial communication standards for communications.Based on next-bit machine for basic goods temperature detected data Tour, the top can achieve the integrated treatment of PC functions or for the expansion of long-distance operation. The entire inspection system is fast, expansion.

    标签: 89C C52 AT 89

    上传时间: 2013-10-13

    上传用户:zhoujunzhen

  • 基于8051F330的音频信号发生器的设计

     MMC/SD卡以其优越的性能,在单片机嵌入式设备中得到广泛应用。将MMC/SD卡作为外部掉电存储介质应用于音频信号发生器中,通过8051F330单片机上的SPI接口,实现单片机—MMC/SD卡的存储扩展,设计了此硬件平台上的MMC/SD卡的单片机驱动程序,并给出了相应的程序代码,满足音频信号发生器的大容量存储要求。 Abstract:  MMC/SD card is more and more widely used in the single chip embedded devices for their excellent performances.This article introduces the application of MMC/SD card as the external power down storage medium in audio signal generator. The extension technology especially for storage of single chip-MMC/SD card via SPI interfaces in 8051F330 single chip, including designs single chip drive program of MMC/SD card based on hardware platform,and also gives the key coding of the program. The implementation of big capacity storage is meaningful in audio signal generator.

    标签: 8051F330 音频信号 发生器

    上传时间: 2014-12-27

    上传用户:黄华强

  • AD9859芯片资料

    FEATURES400 MSPS internal clock speedIntegrated 10-bit DAC32-bit tuning wordPhase noise ≤ –120 dBc/Hz @ 1 kHz offset (DAC output)Excellent dynamic performance>75 dB SFDR @ 160 MHz (±100 kHz offset) AOUTSerial I/O control1.8 V power supplySoftware and hardware controlled power-down48-lead TQFP/EP packageSupport for 5 V input levels on most digital inputsPLL REFCLK multiplier (4× to 20×)Internal oscillator; can be driven by a single crystalPhase modulation capabilityMultichip synchronization

    标签: 9859 AD 芯片资料

    上传时间: 2014-12-04

    上传用户:axin881314

  • MT8870D DTMF解码芯片

    Features• Complete DTMF Receiver• Low power consumption• Internal gain setting amplifier• Adjustable guard time• Central office quality• Power-down mode• Inhibit mode• Backward compatible withMT8870C/MT8870C-1Applications• Receiver system for British Telecom (BT) orCEPT Spec (MT8870D-1)• Paging systems• Repeater systems/mobile radio• Credit card systems• Remote control• Personal computers• Telephone answering machine

    标签: 8870D 8870 DTMF MT

    上传时间: 2013-11-20

    上传用户:mpquest