• AD6645: FAQ

    FAQ

  • AD6645: Overvoltage protection

    Q 

    As we drive the AD6645 with a differential amplifier (AD8138), the question
    comes up if it is necessary to protect the AD6645 from negative voltages at its
    analog input. When supplying the op amp with a +/- supply voltage, the output
    can easily…

  • AD6645: Spurious noise

    Q 

    The problem is related to the A/D converter AD6645 which we use together with
    the AD8351 as preamplifier. The diagram of the input circuit can be provided.
    The signal is then routed to the downconverter AD6634. We use the filters of
    this downconverter…

  • AD6645: Max input signal

    Q 

    please can you tell me how the AD6645 will cope with a continuous sin wave
    signal applied between the Full scale maximum and the absolute maximum input
    rating of the device. We have an error mode where this may occur and I would
    like to know if…

  • AD6645: Interfacing to a FPGA

    Q 

    We intend to use AD6645-105 FADCs running at 100MHz driving into a Xilinx
    Virtex II Pro chip. (7 FADCs into one chip). In the AD data sheet there is a
    test board diagram which uses a 74LCX574 chip to latch the data output from the
    ADC. It shows…

  • AD6645: Selection of resistor values

    Q 

    In the EVM you use two banks of resistor before and after the latches. Does the
    board work with values between 33 and 47 ohm for RN1 and RN3?

     

    A 

    The board will be functional with all values of resistors up to the 470ohms.
    The higher resistance…

  • 关于AD8331和AD6645使用的问题

    ADI工程师：

            您好！我在使用AD6645的时候有点问题，向您请教一下。

            AD8331和AD6645交流耦合，AD8331的VCM引脚输出共模电压2.4V，AD6645的VREF引脚输出2.5V，可以把AD6645的VREF引脚直接和AD8331的VCM引脚连起来吗？

  • AD6645 OVR总为高

    大家好， 最近我设计了一版 AD6645+FPGA的采集电路

    以下是 AD6645前端部分

    经过测量， AD8138 正电压为5.1V， 负电压为 -4.5V （负电压由LM2662产生）

    AD6645的采样差分时钟 enc 由 FPGA的 差分管脚输出 进行驱动。 同时 FPGA通过AD DRY信号的上升沿进行数据采集并传输。

    开始测试：

    图中R19 甩空，不接任何信号，AD采样结果 是  8191 ， OVR=1

    R19接GND，AD结果是50左右（很小）OVR=0

    R19接…

  • RE: AD6645 105MSPS Clock Input

    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    …

  • RE: AD6645-80 Error in ADC Codes

    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    …