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  • calculates Linear Feedback Shift Register(LFSR) mask and seed values for a specific phase shift.

    calculates Linear Feedback Shift Register(LFSR) mask and seed values for a specific phase shift.

    标签: calculates Feedback Register specific

    上传时间: 2017-09-06

    上传用户:fnhhs

  • Delphi snippet to convert variants values to xml

    Delphi snippet to convert variants values to xml

    标签: variants snippet convert Delphi

    上传时间: 2014-12-02

    上传用户:417313137

  • 2012TI电子设计大赛——微弱信号检测装置

    微弱信号检测装置 四川理工学院 刘鹏飞、梁天德、曾学明 摘要: 本设计以TI的Launch Pad为核心板,采用锁相放大技术设计并制作了一套微弱信号检测装置,用以检测在强噪声背景下已知频率微弱正弦波信号的幅度值,并在液晶屏上数字显示出所测信号相应的幅度值。实验结果显示其抗干扰能力强,测量精度高。 关键词:强噪声;微弱信号;锁相放大;Launch Pad Abstract: This design is based on the Launch Pad of TI core board, using a lock-in amplifier technique designed and produced a weak signal detection device, to measure the known frequency sine wave signal amplitude values of the weak in the high noise background, and shows the measured signal amplitude of the corresponding value in the liquid crystal screen. Test results showed that it has high accuracy and strong anti-jamming capability. Keywords: weak signal detection; lock-in-amplifier; Launch Pad  1、引言 随着现代科学技术的发展,在科研与生产过程中人们越来越需要从复杂高强度的噪声中检测出有用的微弱信号,因此对微弱信号的检测成为当前科研的热点。微弱信号并不意味着信号幅度小,而是指被噪声淹没的信号,“微弱”也仅是相对于噪声而言的。只有在有效抑制噪声的条件下有选择的放大微弱信号的幅度,才能提取出有用信号。微弱信号检测技术的应用相当广泛,在生物医学、光学、电学、材料科学等相关领域显得愈发重要。 2、方案论证 针对微弱信号的检测的方法有很多,比如滤波法、取样积分器、锁相放大器等。下面就针对这几种方法做一简要说明。 方案一:滤波法。 在大部分的检测仪器中都要用到滤波方法对模拟信号进行一定的处理,例如隔离直流分量,改善信号波形,防止离散化时的波形混叠,克服噪声的不利影响,提高信噪比等。常用的噪声滤波器有:带通、带阻、高通、低通等。但是滤波方法检测信号不能用于信号频谱与噪声频谱重叠的情况,有其局限性。虽然可以对滤波器的通频带进行调节,但其噪声抑制能力有限,同时其准确性与稳定性将大打折扣。

    标签: 2012 TI 电子设计大赛 微弱信号

    上传时间: 2013-11-04

    上传用户:lty6899826

  • 如何设计升压转换器MAX17597峰值电流模式控制器

    Abstract: This application note describes how to design boost converters using the MAX17597 peakcurrent-mode controller. Boost converters can be operated in discontinuous conduction mode (DCM) orcontinuous conduction mode (CCM). This operating mode can affect the component choices, stress levelin power devices, and controller design. Formulas for calculating component values and ratingsare alsopresented.

    标签: 17597 MAX 如何设计 升压转换器

    上传时间: 2013-11-16

    上传用户:zcs023047

  • 校准触摸屏系统研究

    Abstract: Mechanical misalignment and scaling factors lead to a mismatch between the values coming from a touchscreen panel (as translated by a touch screen controller) and the display (typically an LCD) on which the touch screenpanel is mounted. This tutorial discusses how to calibrate the touch screen panel to match the display.

    标签: 校准 触摸屏 系统研究

    上传时间: 2013-10-21

    上传用户:euroford

  • 计算FR4上的差分阻抗(PDF)

    Calculation of the Differential Impedance of Tracks on FR4 substrates There is a discrepancy between calculated and measured values of impedance for differential transmission lineson FR4. This is especially noticeable in the case of surface microstrip configurations. The anomaly is shown tobe due to the nature of the substrate material. This needs to be considered as a layered structure of epoxy resinand glass fibre. Calculations, using Boundary Element field methods, show that the distribution of the electricfield within this layered structure determines the apparent dielectric constant and therefore affects theimpedance. Thus FR4 cannot be considered to be uniform dielectric when calculating differential impedance.

    标签: FR4 计算 差分阻抗

    上传时间: 2014-12-24

    上传用户:DE2542

  • 零晶体管IC-IC设计一个新高度

    Abstract: We can apply a BiCMOS integrated circuit with only resistors and no transistors to solve adifficult design problem. The mythically perfect operational amplifier's gain and temperature coefficient aredependent on external resistor values. Maxim precision resistor arrays are manufactured together on asingle die and then automatically trimmed, to ensure close ratio matching. This guarantees that theoperational amplifier (op amp) gain and temperature coefficient are predictable and reliable, even withlarge production volumes.

    标签: IC-IC 晶体管

    上传时间: 2014-11-30

    上传用户:ynzfm

  • 电源供应器与数字电位器校准应用笔记

    Abstract: A resistive feedback network is often used to set the output voltage of a power supply. A mechanical potentiometer (pot)conveniently solves the problem of adjusting a power supply. For easier automatic calibration, a mechanical pot can be replaced witha digital pot. This application note presents a calibration solution that uses a digital pot, because digipots are smaller, do not movewith age or vibration, and can be recalibrated remotely. This proposed solution reduces the susceptibility of the system to thetolerance of the digital pot's end-to-end resistance, making the solution optimal fordesigners. This application note also explainssome of the equations required to calculate the resistor chain values and to use a digital pot in this way. A spreadsheet withstandard reisistor values is available for easy calculations.

    标签: 电源供应器 数字电位器 应用笔记 校准

    上传时间: 2013-10-31

    上传用户:caiguoqing

  • 西门子S7-300 PLC模拟量转换

    Analog Inputs and Outputs in an S7 PLC are represented in the PLC as a 16-bit integer. Over the nominal span of the analog input or output, the value of this integer will range between - 27648 and +27648. However, it is easier to use the analog values if they are scaled to the same units and ranges as the process being controlled. This applications tip describes methods for scaling analog values to and from engineering units.

    标签: 300 PLC 西门子 模拟量

    上传时间: 2013-11-17

    上传用户:3294322651

  • 基于AT89C52单片机的语音录放系统

       设计一种基于AT89C52的语音录放系统,利用单片机、ISD2560语音录放器件、麦克风、扬声器等元器件实现硬件电路的设计,并利用C51高级语言设计ISD2560器件控制字的写入和定时中断程序。经软硬件调试,结果表明该系统录放效果良好,具有一定的工程实用价值。 Abstract:  Voice recording and playback system based on AT89C52is designed in this paper.Using the single-chip microcomputer,voice recording and playback chip ISD2560,microphone and speaker to realize the hardware circuit design.Writing ISD2560control words and timing interrupt procedures are designed by C51advanced language.Through the hardware and software test,voice recording and playback system play better voice,and this system has some engineering practical values.

    标签: 89C C52 AT 89

    上传时间: 2013-10-20

    上传用户:ywcftc277