• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 2 answers
  • Subscribers 62 subscribers
  • Views 306 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.

UCD90320: Power on / off

HSU HANWEN
Intellectual 290 points
Part Number: UCD90320


Hi Yihe:

Setting of power on / off on my board is depend on power sequence.

But I want to control it through SMBUS now.

*P3V3, which is supplied to UCD90320 will always on

-

1. How do I turn off power rails

(1) Individually

(2) All rails at the same time

-

2. How do I turn on power rails

(1) Individually

(2) All rails at the same time

  • 0
    TI__Guru 66550 points

    Hi

    You have to follow the following:

    1. set the rail's ON_OFF_CONFIG to OPERATION mode

    2. issue OPERATION command to the desired PAGE to turn on or off.

    If you want to turn on and off all rails at the same, please issue PAGE(0x00) command with PAGE 0xFF first.

    Regards

    Yihe

  • 0 in reply to yihe
    Intellectual 290 points

    Hi Yihe:

    If address of UCD90320 is 17h and want to turn off all power rails at the same time, could you help check if following steps are correct or not?

    -

    1. Set the rail's ON_OFF_CONFIG to OPERATION mode, which control by PMBUS

    17h 02h 18h

    -

    2. Send command to turn off all power rails at the same time

    17h 01h FFh 00h

    or 17h FFh 01h 00h

  • 0 in reply to HSU HANWEN
    TI__Guru 66550 points

    Hi

    For Step 1, you have to change all Rails' ON_OFF_CONFIG to OPERATION instead of just one rail.

    For Step 2. 

    0x17 0x00 0xFF -> select all rails

    0x17 0x01 byte from below to on or off.

    Regards

    Yihe

  • 0 in reply to yihe
    Intellectual 290 points

    Hi Yihe:

    Could you help check following commands?

    -

    1. For step1:

    0x17 0x00 0xFF -> select all power rails

    0x17 0x02 0x18 -> set all power rails to OPERATION mode, which control by PMBUS

    -

    2. If I want change it back to power on (with sequence)

    0x17 0x00 0xFF

    0x17 0x02 0x00

  • +1 in reply to HSU HANWEN
    TI__Guru 66550 points

    Hi

    Yes, it shall work. but you may want to send 0x40 with command 0x02 to soft off instead of immediately off.

    Regards

    Yihe