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TPS65981: PD negotiation loop with Google Pixel

Prodigy 20 points

Replies: 4

Views: 84

Part Number: TPS65981

I'm working on a design which is a UFP. When it is connected to a Samsung Galaxy S9 smart phone, I see the TPS65981 negotiate for the phone to be the power source based on my Sink PDO, as expected:

I get the Source_Capabilities, Request, Accept, and PS_RDY, all with GoodCRC.

However, when I connect the same board to a Google Pixel 3 phone, I get into a strange loop:

The phone sends out the Source_Capabilities message, then the TPS65981 responds with a GoodCRC, followed by a Request, followed by what appears to be a spurious GoodCRC? The phone never issues a GoodCRC, but it does attempt to send an Accept message, which is never acknowledged by the TPS65981. Since the Accept doesn't get a GoodCRC response, the phone starts generating Source_Capabilities messages and the whole process repeats for potentially thousands of messages. The fifth column is the message id; it keeps cycling between 0 and 1.

Eventually, somebody triggers a hard reset of the interface. I'm not sure if it's the phone or the TPS65981. After that, the negotiation works as expected:

It can take up to a minute for the phone to successfully establish a connection. Any ideas on what could be causing this?

I'm using version 4.01 of the Application Customization Tool.

  • Hi Anthony,

    Do you think you could download the latest version of the Application Customization Tool? version 4.03.
    This would ensure you are testing with our latest firmware version.

    Thank you,
    Eric
  • In reply to Eric Beljaars:

    Hi Eric,

    I downloaded the 4.03 version of the Application Customization Tool, built a new firmware image, and loaded it into my device. The behavior is exactly the same.

    Tony

  • In reply to Anthony Hefner0:

    Hi Anthony,

    Could you capture a Scope shot of VBUS and CC during the failure?
    This would tell us if there is any abnormal voltage on either causing the failure.

    Thank you,
    Eric
  • In reply to Eric Beljaars:

    Hello,

    I have not heard back from you in a while.

    If I answered your question, PLEASE select This resolved my issue

    Thank you,
    Eric

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