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DAC81416: Sequential DAC update wait time

Will Wang47
Expert 8160 points

Other Parts Discussed in Thread: DAC81416

Hi Team,

Customer want to use DAC81416 in their projects. They get one question about the spec "Sequential DAC update wait time", what does this mean? Does this mean we should wait 2.4us between each DAC output update? Could you give some comments to this?

Thanks,

Will

  • 0
    TI__Guru 56153 points
    Hi Will,
    My colleague will get back to you on Monday.

    Thanks,
    Paul
  • 0 in reply to Paul_Frost
    TI__Genius 14220 points
    Hi Will,

    Thank you for your query. You're right. The sequential DAC update wait time is the wait time between two consecutive DAC updates. You can go through this short video to understand how DAC update rate is defined.

    Hope that answers your question.

    Regards,
    Uttam Sahu
    Applications Engineer, Precision DACs
  • 0 in reply to Uttam Sahu
    TI__Expert 8160 points
    Hi Uttam,

    Thanks for helping on this. Do you mean which video? Could you share me the link?
    And I also see there is "Streaming Mode Operation", does this also need 2.4us wait time? Could you give some comments to this?

    Thansks and Best Regards,
    Will
  • 0 in reply to Uttam Sahu
    Prodigy 50 points

    Hi Sahu,

    Thank you for your reply. I have some questions for this.You said the sequential DAC update wait time is the wait time between two consecutive DAC updates.This means I should wait 2.4us to set the CH1 register after seting the CH0. So time consumed to operate 16 channels is 2.4us*16+setting time*16 ,is that right? 

    LDAC is synchronization signal. What is the time for synchronous updates of 16 channels? 2.4us or more.

    Regards,

    Chenyang Li

  • 0 in reply to user5162383
    TI__Genius 14220 points
    Hi Chenyang/Will,

    While we are addressing this issue over email, let me post my response here before closing this thread.

    When you send one SPI frame for every DAC update, they need to respect the update wait time irrespective of whether they use LDAC or not.

    However, as you mentioned, in the streaming mode, you can update all the channels in one go and then assert LDAC or CS to update them.

    Sorry for missing the training video on the update rate in my last post. Please find it here:

    training.ti.com/lessons-precision-dacs-settling-time-vs-update-rate

    Regards,
    Uttam