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variable-Frequency

  • DN460双输出降压稳压器优化效率

      The LTC3546 is a dual output current mode buck regulatorwith fl exible output current partitioning. Beyondthe advantages normally associated with dual outputregulators (reduced size, cost, EMI and part count, withimproved effi ciency), the LTC3546’s outputs can bepartitioned for either 3A and 1A outputs, or two 2A outputs.This increases its application range and simplifi esmultiple supply rail designs. A confi gurable Burst Mode®clamp for each output sets the current transition levelbetween Burst Mode operation and forced continuousconduction mode to optimize effi ciency over the entireoutput range. An adjustable switching frequency up to4MHz and internal power MOSFET switches allow forsmall and compact footprints.

    标签: 460 DN 输出 优化效率

    上传时间: 2013-11-04

    上传用户:yxgi5

  • DN457宽输入电压范围同步降压稳压器

      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.

    标签: 457 DN 同步降压

    上传时间: 2013-11-07

    上传用户:moerwang

  • 超低功率转换器的控制方案消除开关噪声

      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.

    标签: 超低功率 控制 开关噪声 方案

    上传时间: 2013-10-21

    上传用户:非衣2016

  • 开关稳压器的偏置低噪声变容

      Telecommunication, satellite links and set-top boxes allrequire tuning a high frequency oscillator. The actualtuning element is a varactor diode, a 2-terminal device thatchanges capacitance as a function of reverse bias voltage.1 The oscillator is part of a frequency synthesizingloop, as detailed in Figure 1. A phase locked loop (PLL)compares a divided down representation of the oscillatorwith a frequency reference. The PLL’s output is levelshifted to provide the high voltage necessary to bias thevaractor, which closes a feedback loop by voltage tuningthe oscillator. This loop forces the voltage controlledoscillator (VCO) to operate at a frequency determined bythe frequency reference and the divider’s division ratio.

    标签: 开关稳压器 低噪声 变容

    上传时间: 2013-12-20

    上传用户:ABCDE

  • SKS-100 Single Output Switchin

    Features:   High efficiency, high reliability, low cost  AC input range selected by switch  100% full load burn-in test  Protections: Short circuit / Over load  Fixed switching frequency at 25KHz  Cooling by free air convection  1 year warranty   Dimensions: 199*98*38mm (L*W*H)    

    标签: Switchin Output Single SKS

    上传时间: 2013-10-30

    上传用户:taa123456

  • 电源滤波器POWER LINE FILTERS

    应用 APPLICATIONS·电视机、录像机、音频设备、显示器、复印机、打印装置、游戏机及计算机等。·用于开关电源线性滤波器。·削除 TV、VTR、VCR及监听器泄漏杂音。·用于OA 设备、通信设备和其它器件。·TV set, recorder, sound-frequency equipment, show-scope, photocopy-scope, typewrite equipment, recreation-scope, computer etc.·For line filters of switching power supplies.·Eliminates incoming/leaking noise of TVs, VTRs/VCRs and audio equipment .·For OA equipment, communications equipment and other electronic devices.

    标签: FILTERS POWER LINE 电源滤波器

    上传时间: 2013-10-23

    上传用户:shizhanincc

  • MAXX9257 MAX9258芯片可编程SerDes持续时间计算

    The MAX9257/MAX9258 programmable serializer/deserializer (SerDes) devices transfer both video data and control signals over the same twisted-pair cable. However, control data can only be transmitted during the vertical blank time, which is indicated by the control-channel-enabled output (CCEN) signal. The electronic control unit (ECU) firmware designer needs to know how quickly to respond to the CCEN signal before it times out and how to calculate this duration. This application note describes how to calculate the duration of the CCEN for the MAX9257/MAX9258 SerDes chipset. The calculation is based on STO timeout, clock frequency, and UART bit timing. The CCEN duration is programmable and can be closed if not in use.

    标签: SerDes MAXX 9257 9258

    上传时间: 2014-01-24

    上传用户:xingisme

  • 基于PIC18F1320微控制器的信号采集系统

      便携式信号采集在机器健康诊断系统中有较高的应用价值。机器健康诊断的信号特点是包括低频信号。本文研究是为了实现简易而且低成本的低频便携式信号采集。以Microchip公司单片机PIC18F1320为核心设计信号采集电路,实现了信号的采集和保存。系统采用串行电可擦除芯片24LC32A保存数据,经过有线通信,信号数据由串行口通过MAX232芯片输送到微型计算机接收和保存,最后绘制出信号波形。 微型计算机程序采用Visual Basic编程。研究成功采样频率为3 kHz的复杂信号,证明该方案符合设计要求。   Abstract:   Portable signal acquisition is useful in machine health monitoring systems. The signal characteristics of machine health monitoring includes low frequency signals. The goal of this study is to realize simple, inexpensive and portable low frequency signal sampling. This paper provides the project of signal acquisition system design based on PIC18F1320 microcontroller manufactured by the Microchip Technology Incorporation to achieve signal sampling and storage. The system adopted EEPROM 24LC32A to store the signal data. The microcomputer received data via wired link with the MAX232 IC through the serial port. The microcomputer program, programmed in Visual Basic, received the data, stored it and plotted the signal. The study successfully samples 3kHz complicated signals and thus meets the design requirement.

    标签: F1320 1320 PIC 18F

    上传时间: 2013-11-19

    上传用户:moerwang

  • 基于MSP430F1611单片机的音频信号分析仪设计

      为了使音频信号分析仪小巧可靠,成本低廉,设计了以2片MSP430F1611单片机为核心的系统。该系统将音频信号送入八阶巴特沃兹低通滤波器,对信号进行限幅放大、衰减、电平位移、缓冲,并利用一单片机负责对前级处理后的模拟信号进行采样,将采集得到的音频信号进行4 096点基2的FFT计算,并对信号加窗函数提高分辨率,另一单片机负责对信号的分析及控制显示设备。此设计精确的测量了音频信号的功率谱、周期性、失真度指标,达到较高的频率分辨率,并能将测量结果通过红外遥控器显示在液晶屏上。   Abstract:   o make the audio signal analyzer cheaper, smaller and more reliable, this system sends the audio signal to the eight-order butterworth filter, and then amplifies, attenuates, buffers it in a limiting range, transfers the voltage level of the signal before utilizing two MSP430F1611 MCU to realize the audio analysis. One is charged for sampling and dealing with the processed audio signal collected by the 4096 point radix-2 FFT calculation and imposes the window function to improve the frequency resolution. The other one controls the display and realizes the spectrum, periodicity, power distortion analysis in high resolution which is displayed in the LCD screen through the infrared remote control.

    标签: F1611 1611 430F MSP

    上传时间: 2013-12-11

    上传用户:jasonheung

  • 基于AVR的新型防汽车追尾安全装置设计

    针对目前汽车追尾事件频发问题,提出一种防汽车车前和车后追尾的安全装置设计。该设计以高性能、低功耗的8位AVR微处理器ATmega8L为核心,结合霍尔式车速传感器、激光雷达测距装置和MMA7260QT加速度传感器,能够兼顾车前和车后,摒弃以往设计中只考虑车前或车后单一性缺点,尤其适用于高速、夜晚或新手行车。 Abstract:  Aiming at the high frequency of vehicle rear-end collision,a safe device design of anti-vehicle rear-end collision is presented.In the design,the high-performance,low-power8-bit AVR microprocessor ATmega8L is utilized as a core combined with Hall-type speed sensor,laser-radar ranging devices and the acceleration sensor MMA7260QT.The design considers both the front and back of a car,and overcomes the drawbacks of former designs in which only the front or the back of the car is considered,so it is especially suitable for high-speed,night or the beginner’s driving.

    标签: AVR 汽车追尾 装置

    上传时间: 2013-10-14

    上传用户:GavinNeko