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ADC12DJ3200EVM: FT_IO_ERROR when writing register 0x08 of LMX2582

Part Number: ADC12DJ3200EVM
Other Parts Discussed in Thread: LMX2582


I am trying to configure my ADC12DJ3200EVM to operate with a 10 MHz reference input to CLKIN0. I am using the ADC12DJxx00 GUI to program the board, but it keeps having a communication error when trying to write to register 0x08 of the LMX2582. It happens when I try to use the EVM GUI, or when I try to load a configuration file in the "Low Level View". Here is a picture of the error message. I am able to immediately reconnect to the device by clicking "Reconnect FTDI?".

I've attached the configuration file I am trying to write to the board. It came with the ADC12DJxx00 GUI software.


Let me know if you need any more info.

Thank you,


  • Hi Alex,

    I'm going to take a look into this with my board. Are you seeing this message at any other time, like when booting the GUI?



  • Hi Drew,

    No, I only see this message when programing the board. Booting the GUI and connecting to the device work fine. It always happens when it gets to register 0x08 of the LMX2582 and never any other time.

    Thank you,


  • Thank you Alex,

    I am working on finding a solution for you on this. Your cfg file appears correct, so I will check with a 10 MHz reference into J38 and see what I find. I will try to post an update by tomorrow.



  • Hi Alex,

    Upon some testing, I have found that the GUI produces a scenario like you described when I limit the peak current to about 1.9 A (at 5 V). What are you using to power your EVM?

    If your supply can't draw the necessary current, it's likely that your USB voltage will drop to compensate, effectively severing the connection to the GUI, albeit successfully programming the LMX configuration.

    If it works when you click 'Reconnect,' then it's reestablishing the USB handshake without simultaneously needing current to program, so you're able to reconnect that way. If I immediately click 'Reconnect' repeatedly, it takes 3-4 clicks. If I wait about three seconds, it only takes one click, suggesting the USB connection is stabilizing. See if this is the case with your setup as well.

    What is the output current compliance limit/current rating of your 5V supply? If your voltage is as clean as mine, my guess is it's less than 1.5 A. Let me know what those specs are and check your 5V rail at your board.