• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 63 subscribers
  • Views 401 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

TPS549A20: PMBus address can be set to 0x26 or not?

TPS549A20: PMBus Vout settings store to NVM

Jerry%20Leung
Intellectual 905 points
Part Number: TPS549A20
Other Parts Discussed in Thread: TPS53659

Hi Team,

I have a customer using the TPS549A20 and are doing some power cycling on their mfg tests.  They have been using VOUT_MARGIN to adjust the voltage but noticed that when they toggle the enable to power cycle their output voltage falls back to the default settings. Is there a way to store the settings to NVM with this device? 

I noticed there's also the VOUT_ADJUSTMENT command, could you use that command with STORE_DEFAULT_ALL to store the register settings to NVM?

Thanks for the help and best regards,

Jerry

  • 0
    TI__Guru**** 191445 points
    Jerry,

    The STORE_DEFAULT_ALL [11h] (Send Byte) copies the entire contents of the operating memory to the corresponding locations in NVM.
  • 0 in reply to JohnTucker
    TI__Intellectual 905 points

    Hi John, 

    Thanks for the insight here.  I forgot to mentioned this in the initial post but I did actually have our customer try Vout Margin followed by the STORE_DEFAULT_ALL command, he mentioned that after power cycling the Vout went back to the Vboot voltage.  He confirmed this with a separate multi-phase device (TPS53659) which supported PMBus fully, but would it have a similar case with the TPS549A20?

    Our other product line mentioned that they should be setting the voltage with VOUT_COMMAND and margining is more for on the fly adjustment. However, it seems that the VOUT_COMMAND is not supported by the TPS549A20.  Is there a similar method that they should be setting Vout? 

    Thanks for the help and best regards,

    Jerry

  • 0 in reply to Jerry%20Leung
    TI__Guru**** 191445 points
    Jerry,

    The VOUT_MARGIN and VOUT_ADJUSTMENT registers are in fact stored in NVM and can be changed from the NVM default values, However setting those values in NVM do not actually change the output voltage. The voltage is changed when OPERATION<5:2> command is issued.