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TPS65988: Can TPS65988 cut off VBUS power from SOURCE side

Di Fang
Prodigy 10 points
Part Number: TPS65988

Currently TPS65988 Port1 is the sink role, for some reasons, I want to cut off the vbus input from the Source side to the TPS65988 Sink, and no longer supply power to the TPS65988 Sink

At present, I want to use the "DISC" command to test, but the TPS65988 response is all !CMD
Is there a suggested way to provide it?

  • 0
    TI__Mastermind 32791 points

    Try writing the . 0x28 Port Configuration Register to set the TypeCStateMachine to 0x11.  This should cause a disconnect and the port not to connect again until you return them to the sink state.

  • 0 in reply to Chuck Branch
    Prodigy 10 points

    Modify TPS65988 Port1 Sink side TypeCStateMachine = 0x11, Vbus loops from 20V→0V→5V, it seems to be cut off and then restarted.

    When I am the TPS65988 Port2 Source side (power transmission side) and set TypeCStateMachine = 0x11, Vbus can be cut off normally.

    But when I am the sink end (the receiving end), there will be a 20V→0V→5V infinite loop state

    STEP1

    STEP1

    STEP 2

    STEP2

    STEP 3

    STEP3

  • 0 in reply to Di Fang
    TI__Mastermind 32791 points

    Di Fang,

    I need to look at the documentation to see if we can reduce the sink PDO support to 0 through the host interface to execute this command.  The statemachine change seems to have destabilized the firmware based on the results that you are seeing.

    When you attempted the DISC command, did you use a delay of 0?

    I will get back to you on Thursday with an update and recommendation.

  • 0 in reply to Chuck Branch
    Prodigy 10 points

    Since the Application Customization Tool was used during the test, the situation that caused the continuous restart should be that my screen was always in the Configuration Registers, which caused the Application Customization Tool to set the TypeCStateMachine to 0x11 after the restart.

    Is there a way to cut off the communication and power supply from the Sink side to the Source side, and only by re-plugging and unplugging the Type C can the Source repower the Sink?

    When you attempted the DISC command, did you use a delay of 0?

    Send 4CC "DISC" command using Application Customization Tool

  • 0 in reply to Di Fang
    TI__Mastermind 32791 points

    Di,

    When you send the 4CC DISC command, you have to include an 8 bit field that is the delay.   If you set the delay to 0,, then it should permanently disconnect the port until you issue a GAID command to reset the port.

    Regards,

    Chuck

  • 0 in reply to Chuck Branch
    Prodigy 10 points

    Hi

    1.I currently use the Application Customization Tool to connect the tps65988 I2C2, send the "DISC" command to Port1 (Sink), and the response is !CMD

    2.When my power is supplied by Power PD to TPS65988 Port1(Sink), does TPS65988 have a command to make Power PD turn off communication and power?

    3.tps65988 port1 (Sink) configures the TypeCStateMachine register = 11b in the 0X28 address, is it only possible to temporarily disconnect the communication and power supply?

    4.Currently use Application Customization Tool to connect I2C2 of TPS65988, configure TypeCStateMachine station register = 11b in 0X28 address, you can always disconnect and reconnect countless times, but use MCU to connect I2C1 of TPS65988, configure TypeCStateMachine station register = 11b, After disconnecting and reconnecting about 5 to 6 times, there will be no response, VBUS is also 20V, is this normal?

    5.When the working power of TPS65988 comes from Power PD, the "DISC" command and The function of configuring the 0x28 register can only cut off the communication and Vbus temporarily?

  • 0 in reply to Chuck Branch
    Prodigy 10 points

    I would like to know if the TPS65988 Port 1 (SINK) is powered only from the Power PD (there is no other backup power supply to keep the TPS65988 working), is there a way for the TPS65988 Port 1 (SINK) to order the Power PD to cut off the VBUS and communication?

  • 0 in reply to Di Fang
    TI__Mastermind 32791 points

    DI Fang,

    If you do not have a backup power supply, then there is no way to the TPS65988 to retain a disconnect.  It will lose power, then boot back up in the dead battery connection and then make the selected connection.

    Regards,

    Chuck