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TPS65986: HPD for displayport

Part Number: TPS65986

Dear Sir 

May application is docking (TypeC DP UFP)

When I insert the DP cable and TypeC cable first then I plug the power jack ,the monitor can't display normally ,

I need to re-plug DP cable again then the monitor can display normally 

Do you have any idea how to solve this issue ?

May I know the HPD signal need to wait TPS6598x CC communication finish or into display alternate mode ??  

what's value for minimum IRQ timing ? 

  • Hi Kai, 

    The minimum IRQ timing and can be seen in section 6.24 HPD Timing Requirement of the datasheet. There should not be an issue using the 986EVM in dead battery mode and having the PR swap and then  DR swap so that monitor displays properly. If possible can you provide PD traces using a LeCroy PD analyzer?

    Regards,

    Jimmy Hua

  • Dear Jimmy

    Yes!! I disable the Power role swap function ,but still have dead battery in my schematic 

    I would like to do power source only and DP sink on my typeC port

    My test setting is 

    TPS65986EVM set DP source and power sink (CFG 1)

    My board is DP sink and power source 12V/3A

    I meet a issue 

    If I use reference code as below setting ,When I remove power jack ,the TPS65986EVM will change from power sink to power source 

    When I re-plug in power jack ,TPS65986EVM still keep power source not change to power sink

    When I use below setting ,the DP can't display normally when I insert DP and TYpeC cable first then plug in power jack 

    My target is 

    1, When I insert TypeC and DP cable first and then plug in power jack ,the DP display can work normally 

    2. When I remove power jack ,TPS65986EVM will not change to power source and this moment I replug power jack ,my board can do power source to supply 12V/3A to TPS65986EVM

    Thanks

  • Hi Kai,

    It's difficult to debug without having PD traces from a PD analyzer. Can you provide PD trace information and use the App Customization Tool under Debug Mode to send Snapshots of the following conditions:

    • Normal working condition
    • DP cable and USB Type-C cable plug (no power jack)
    • Connected with power jack

    One concern I have right now is whether or not HPD is being properly detected between your board and the TPS65986EVM. Correct me if I'm wrong, with the recent message, your setup looks something like Laptop ->986EVM - your board -> DP monitor. Am I correctly?

     What type of PD device are you using on your board?

    Regards,

    Jimmy Hua

  • Hi Kai,

    I noticed you didn't answer this post. If you don't have any more questions on this, I would like to close this thread.

    Regards,
    Jimmy Hua
  • Hi Kai,

    Were you ever able to solve your issue? how did you get DP to pass?

    Thanks