• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 62 subscribers
  • Views 399 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

UCD92xx How to change output voltage in runtime

Gunnar Alm
Prodigy 20 points
Other Parts Discussed in Thread: UCD7242, UCD9224

Hi,

I am using the UCD9224 with the UCD7242 and it works fine. I program the UCD9224 at production time and one of its rails delivers 1.025 V for a processor core supply. When the processor is started I will find out its recommended operating voltage for the core and I then need to change the 1.025 V to make it deliver a somewhat lower voltage.

This will be done in runtime so I have obviously not the Fusion software or the PMBus USB dongle available. Instead, my processor is connected to the UCD9224 PMBus and I need to send a few commands to the UCD9224 to make it change its ouput voltage.

Can someone please show where I can find information on how to make this happen (which commands and what data formats)?

Thank you in advance!

Regards,

/Gunnar Alm

  • 0
    TI__Genius 13700 points

    The UCD92xx PMBus Command Reference lists commands supported by the UCD92xx line of controllers and provides implementation details on the Manufacturer Specific commands.  For implementation details on standard PMBus commands, refer to the PMBus specification.  The UCD9224 supports version 1.1 of the PMBus specification.

    UCD92xx PMBus Command Reference:  www.ti.com/lit/ug/sluu337/sluu337.pdf

    PMBus Specification:  www.pmbus.org

     

  • 0 in reply to Brad
    Prodigy 20 points

    Thanks for the quick answer, I suppose I had it coming because I wrote the question the way I did.

    I have read the UCD92xx PMBus Command reference and I am well aware on the PMBus standard but need to be sure I issue the right commands and in the right order. So what I should have asked for is if there are some info on which commands and in which order are needed to change the output voltage on rail #2 in runtime.

    If there are no such information then maybe I can ask straight out if it will work by issuing the following three commands:

    - PAGE

    - PHASE

    - VOUT_COMMAND

    I do not intend to write the new output voltage value to the UCD9224 flash.