• RE: Nonlinear output of ADC AD7643

    Hi harrycheung,

    Thanks you for the schematic and the data.

    I have checked your data and from there, it is showing that the output code is 11bits with MSB as the sign bit, 1 positive and 0 neagtive.The equivalent voltage was computed using the LSB size…

  • RE: Which reference should be used with the AD5541A/42A?

    Suitable external references include the ADR421 and ADR431.Both are low noise reference sources and have the required noise/accuracy level to achieve the best performance from the AD5541A/42A.

    The reference buffer is also critical to the design because…

  • RE: AD7691 Pulsar Differential ADC Common Mode Input Spec

    Hi Shane,

    The reference must be capable of supplying the average current needed to top up the reference capacitor without causing the reference voltage to droop significantly. Insufficient drive strength is an issue, especially if low-power references…

  • AD7982: Driving the reference input

    I am currently designing a circuit that uses a pulSAR ADC, specifically the
    AD7982, and am having difficulties understanding the choice of components
    required for driving the reference pin.

    The data sheet for the device recommends using…
  • 深度技术分享——ADC基准电压源设计中的挑战和要求

    本文转自电子工程专辑http://www.eet-china.com/ART_8800689587_617703_TA_97e1eef8.HTM

    高分辨率、逐次逼近型ADC的整体精度取决于精度、稳定性和其基准电压源的驱动能力。ADC基准电压输入端的开关电容具有动态负载,因此基准电压源电路必须能够处理与时间和吞吐速率相关的电流。某些ADC片上集成基准电压源和基准电压源缓冲器,但这类器件在功耗或性能方面可能并非最佳——通常使用外部基准电压源电路才可达到最佳性能。这篇文章将探讨基准电压源电路设计中遇到的挑战和要求…

  • RE: 成功进行模数信号转换的七个步骤

    第1步:描述传感器或增益模块前部的电气输出

      信号可能直接来源于传感器,也可能在到达增益模块之前经过EMI和RFI滤波器。为了设计增益模块,必须知道信号的ac和dc特性以及可用的电源。知道了信号的特性和噪声电平后,我们就能知道选择ADC时需要何种输入电压范围和噪声电平。假设有一个传感器,以250 mV p-p(88.2 mV rms)和25 μV p-p噪声的满量程幅度输出一个10kHz信号。我们进一步假设系统中有一个可用的5V电源。有了这些信息,我们应该能计算出第2步中的ADC输入端的信噪比…

  • 为实现正确信号调理的噪声计算,这七个步骤你得get

    高精度应用需要精心设计的低噪声模拟前端来获得最佳信噪比(SNR),这就要求采用明智的方法来选择ADC以全面准确地捕捉传感器信号。还要选用驱动运算放大器和基准电压源等支持器件来优化电路性能。

    振动、温度、压力和光等现实世界的信号需要精 确的信号调理和信号转换,才能在数字域中进 行进一步数据处理。为了克服高精度应用的多 种挑战,需要一个精心设计的低噪声模拟前端来实现最佳 信噪比(SNR)。但许多系统既负担不起最昂贵的器件,也 无法承受低噪声器件的更高功耗。本文解决有关利用噪声 优化方法来设计完整解决方案的问题…