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TPS65987DDJ: TPS65987DDJ

user5972519
Prodigy 40 points

Part Number: TPS65987DDJ

Dear all.
I would like ask you about "TPS65987DDJ".
I am designing a board, using in above.
I have been troubled in following issue.
When you connect your own board to the USB-PD adapter and turn on the power, 5V is generated.
9V, 15V, 20V also generate voltage when you press each button.
The 5V button is connected to the HRESET terminal with a pull-down connection.
If you press here, the voltage will be 0V and will not be reset.
At that time, the VBUS voltage does not change.
This circuit is based on USB-C-PD-DUO-EVM.
USB-C-PD-DUO-EVM will reset when you press the 5V button.
I would be grateful if you have any resolusion in above.

Best regard.
susumu kikuchi.

  • 0
    TI__Genius 9630 points

    Hello,

    This should be default behavior. Can you attach your schematic?

    Thanks,

    Emma

  • 0 in reply to Emma Hoying
    Prodigy 40 points

    Dear Emma
    Thank you for answering the question.

    I attached the circuit diagram.
    Best regard.
    susumu kikuchi.

  • 0 in reply to user5972519
    TI__Genius 9630 points

    Hello,

    It appears that you have the HRESET pin unwired. It is pin 44. If the pin is not connected, you will not be able to reset the device.

    Thanks,

    Emma

  • 0 in reply to Emma Hoying
    Prodigy 40 points

    Dear Emma
    Thank you for answering the question.
    I attached wrong circuit diagram.
    The 5V SW line is properly connected to the HRESET pin.
    I re-attached the correct it diagram.
    Sorry in confusion.

    susumu kikuchi.

  • 0 in reply to user5972519
    TI__Genius 9630 points

    Hi Susumu-san, 

    Have you been able to reproduce this behavior on other boards? Your schematic appears to be fine. Can you confirm the 3.3V voltage is good on LDO_3V3? Can you also confirm your push button is working as expected?

    Thanks,

    Emma

  • 0 in reply to Emma Hoying
    Prodigy 40 points

    Dear Emma
    Thank you for answering the question.

    My goal:
    With USB-C-PD-DUO-EVM, when you press the 5V push button, the voltage drops once and then the reset operation is performed.

    Description:
    On the board I made, after pressing the 5V push button, the voltage drops to 0V and does not restart.

    Check list:
    -The LDO voltage is 3.3v. There is 3.3v even after performing HRESET.
    -When you press the 9v, 15v, 20v push button, you can check the waveform by observing the CC2 terminal with an oscilloscope.

    Unfortunately, no waveform appears in CC1.

    I customized it circlut for my customer's request.

    Please see the picture in attachment.

    I believe TPS65987DDJ malfunction is not surface mounted on the board.
    What do you think?

    I would be grateful if you have any suggestion.

    Best regard.
    susumu kikuchi.

  • 0 in reply to user5972519
    TI__Genius 9630 points

    Hi Susumu-san, 

    Yes you could be experiencing some issues coming from having the IC connected to the board the way that you do. Are you able to test this on a pcb with the IC surface mounted?

    Also, as a note, TPS65987DDJ is for PC Host systems and Thunderbolt Devices. All other systems should use TPS65987DDH. 

    Thanks,

    Emma