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AFE7769-3P5EVM: TX QMC and LO correction

tamer gudu
Prodigy 140 points
Part Number: AFE7769-3P5EVM
Other Parts Discussed in Thread: AFE7769

Hi team,

At the TX output of the AFE7769 I am seeing a unwanted spurious tones at  and around the local oscillator frequency (3.5GHz). By thinking that it is caused from the 

LO leakage , I want to activate the LO and QMC routine in the AFE7769 through Latte software. For this purpose, (I am using AFE7769-3.5EVM with ZCU111 FPGA board)

1. I connected TX 1 to FB1 

2.Add

    sysParams.enableTxIqmcLoITrackingCorr = True

    sysParams.txIqmcExternalDelayValue = [0,0,0,0]

   sysParams.txIqmcFullBandEstimation = True

   sysParams.txIqmcCalibMode = 0

    AFE.TOP.TIMINGCTRL.txToFbSelectCh(1,0) lines to my Python script to override FBLOOP pins and indicate that FB1 is connected to TX1

When I configure AFE7769 EVB though Latte software and with my new Python script and nothing changed.  I cannot observe anything.

So my questions are:

1. Is there anything more to activate LO correction.

2. How can I check whether QMC and LO correction is working or not?

2. Do you have a Latte Script that sets the QMC and LO correction?

Have a nice day,

Dr. Tamer Güdü

  • 0
    TI__Expert 3515 points

    Hi,

    The steps you followed to run QMC are not fully correct and that's probably the reason for not seeing a difference. 

    1. Latest version of Latte is 2.20. Please update your Latte version if that's not what you have.

    2. You don't need to add "sysParams.txIqmcExternalDelayValue".

    3. Add the other 3 parameters to your bring-up script and run it once. The sysParams you added take effect only after the bring-up script is run.

    4. Please band-pass filter the TX1 output before feeding into FB1 to avoid aliasing. This requirement is explained in section 7 in SBAA370a

    The command you used to run the QMC is correct. Please try with the above changes.

     

    Regards,

    satish.

  • +1 in reply to Satish Uppathil
    Prodigy 140 points

    Hi Satish,

    Thanks for your help. First of all I saw that  my Latte version is older than 2.20. Could you share the link for 

    newest Latte version with upgrade instructions.

    Have a nice day,

    Regards,

    Tamer.

  • 0 in reply to tamer gudu
    TI__Expert 3515 points

    Hi,

    I have asked the local TI engineer supporting your account to forward the link.

    regards,

    satish.

  • 0 in reply to tamer gudu
    Prodigy 140 points

    Thanks Satish. It works.