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TPS659037: Start without a PUSH-Button? (clarification about SLIU011F)

AnBer
Mastermind 30120 points
Part Number: TPS659037
Other Parts Discussed in Thread: AM5728

Team,

a)The below E2E post advise to use the LDOVRTC_OUT on the POWERHOLD/GPIO_7:
https://e2e.ti.com/support/power-management/f/196/p/712129/2624316#2624316
https://e2e.ti.com/support/power-management/f/196/p/744364/2751033#2751033

However the SLIU011 at page 6 Fig 3 just show just an EN signal (without description).

-Can you confirm the logic level and rise edge specs that need to be used on POWERHOLD/GPIO_7?

b) Are there requirements to pull BOOT1 high during the startup of the device (without push-button)?

c) Can you confirm that RESET_IN and NSLEEP need to be connected to VRTC as shown in page 6 Fig. 3?

d) As proof of concept:
what would be the HW changes needed on the TI AM5728 IDK board (TMDXIDK5728) to have the TPS659037 start WITHOUT push button?
The schematics/PCB are available at: http://www.ti.com/tool/tmdxidk5728#technicaldocuments

Thanks in advance,

A.

  • 0
    TI__Genius 10000 points
    AnBer,

    When using POWERHOLD (GPIO_7) to turn on the PMIC, the device will turn on when POWERHOLD sees a "high" logic level. The device will remain on until the input of GPIO_7 goes to a "low" logic level.

    The BOOT1 should still be pulled to VRTC. by pulling this pin high, the RESET_OUT signal will have an additional toggle at the end of the power up sequence. This addresses one of the errata on the TI processor where the PORz pin requires this input.

    RESET_IN and NSLEEP should still be pulled up to VRTC.

    For the IDK schematic, if you wanted to get rid of the push button, all you would need to do is remove the components on the PWRON pin of the PMIC (leave this pin floating) and then use GPIO_7 to turn the PMIC on/off.

    Please let me know if you have any additional questions.

    Thanks,
    Nastasha
  • 0 in reply to Nastasha
    TI__Mastermind 30120 points

    Hi Natasha,

    Nastasha said:
    When using POWERHOLD (GPIO_7) to turn on the PMIC, the device will turn on when POWERHOLD sees a "high" logic level. The device will remain on until the input of GPIO_7 goes to a "low" logic level.



    Is POWERHOLD (GPIO_7) edge or level triggered?
    What are the POWERHOLD (GPIO_7) logic levels electrical specification?

    EDITED: The GPIO_7 electrical specs are given in section 4.16. VRTC is the reference voltage rail.

    Thanks in advance,

    A.

  • 0 in reply to AnBer
    TI__Genius 10000 points
    AnBer,

    GPIO_7 is level triggered. The logic levels are located in the spec table of the datasheet.

    Thanks,
    Nastasha
  • 0 in reply to Nastasha
    Prodigy 50 points

    Hi Natasha,

    First of all, thanks for your support.

    you say:

    "if you wanted to get rid of the push button, all you would need to do is remove the components on the PWRON pin of the PMIC (leave this pin floating) and then use GPIO_7 to turn the PMIC on/off"

    But PWRON pin doesnt have any circuit  except the switch and a ESD protection. This is equivalent to leave the pin floating. But the board still needs the push-button to start-up.¿?

    All i nned is to start up the board without the push-button.  With Beagle black this is possible mounting the jumper (J5).

  • 0 in reply to user4420026
    TI__Genius 10000 points
    AnBer,

    The PMIC does not need a push button to turn on. This can be removed from the board. You can just use GPIO_7 to turn on the PMIC (pull it high).

    Thanks,
    Nastasha
  • 0 in reply to Nastasha
    Prodigy 50 points

    Natasha,

    It doesn´t work with Industrial EVM. It has a mistake. GPIO7 is pulled high.

    But, and this is the problem, is connected to 3V3. This is the reason the EVM industrial will never start without button.

    I made a change in the EVM pcb connecting GPIO7 to LDO_VRT and it works. For this you have to move out of the footprint R18 and rewire.

  • 0 in reply to user4420026
    TI__Genius 10000 points
    Hi,

    Pulling GPIO_7 to VRTC should work and keep the board always-on. If that is what is intended, then you should be good to go. If you need a way to disable the board, You might need to connect the GPIO_7 to a signal that can be turned on and off.

    Thanks,
    Nastasha