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ADC12D1800RFRB: Output at the connector of the reference board

Part Number: ADC12D1800RFRB

Hello,

We are using the ADC12D1800RFRB and have attached a board we designed in order to get the output onto an oscilloscope. We are however, having difficulty getting the bits to display, so we are assuming the output data isn't reaching the connector properly. This leads me to my first question: is there anything we have to do in order to get the output to the connector to display. My second question is: What would the threshold voltages for those bits be?

Thank you,

Edgar

  • Hi Edgar

    I believe the FMC DCLK and DATA signals are enabled by default in the firmware.

    The signals are LVDS_25 outputs from the Virtex-4 FPGA.

    Best regards,

    Jim B

  • Is there any documentation that supports that because the signals are still not present at the output of the FPGA connector. We are positive that the ADC is functioning, as we have simultaneously displayed the output in WaveVision.

    Thanks,
    Edgar
  • Hi Edgar

    I checked this using an ADC12D1800RFRB in the lab today.

    Here are the steps I followed:

    1. Wavevision 5 software is already installed on the PC.
    2. Connect 12V DC power supply (3A rated) to the EVM and turn on the power supply.
    3. Turn on the EVM power switch.
    4. Connect the USB cable to the PC and EVM, let the drivers install if needed.
    5. Launch Wavevision 5 software.
    6. Wavevision 5 software recognizes the board, downloads firmware and configures the on-board clock chip.
    7. At this point the signals are available at the FMC connector.

    I verified signals at the FMC by using a high speed oscilloscope to measure a few different signals. The signals are LVDS, with approximately 1.25V common mode voltage and 150mV peak to peak swing for the plus and minus signals when measured with a single ended probe.

    The DCLK signals are continuous, and the Data signals change behavior as expected when enabling and disabling the Test Pattern Mode of the ADC.

    Please try confirming the signals are there with an oscilloscope. If they are there but the FPGA still doesn't recognize them please let me know which FPGA capture board you are using. In the past we have had some issues where FPGA Carrier Card boards needed a particular status or power signal connection on the ADC EVM. If that connection is not there it can inhibit proper operation of the FPGA banks related to the FMC connector.

    I hope this is helpful.

    Best regards,

    Jim B