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TPS65987DDJ: Process Swap to Sink, and Process Vconn Swap function and behavior

Sai Loo
Expert 4380 points
Part Number: TPS65987DDJ
Other Parts Discussed in Thread: TPS65987D

Hi Team,

In my customer design, as it is a monitor, we set the port as DRP with TrySrc, and select the following setting.

However, in PD3 certification test, there is a test that the tester will test the DUT to be a sink, and will force a current to the DUT. In this case, as the monitor is a sourcing only, and will not sink current, we did not check the "process swap to sink", and it will fail the test, and should get a wavier.

My customer would like to know the behavior if we check the "process swap to sink", what will be the behavior that we could expect?

Another question is regarding the "Process Vconn swap". If we uncheck this, do we expect that during initial plug-in, the PD will not provide the 5V to Vconn? or it is just do not process the Vconn swap request when the platform wanted to pass back the Vconn to the PD?

Regards

SK Loo

  • 0
    TI__Mastermind 36751 points

    Hi SK,

    If the "Process Swap to Sink" bit is enabled, then the TPS65987D will accept a power role swap to become a sink when the connected device is initiating the power role swap. It will not send a Powe Role Swap to become a sink on its own, it will only accept a power role swap if it receives one. The Process VCONN Swap behavior works the same. If the monitor attaches as the DFP, source, and VCONN Source, it will provide VCONN. If the Process VCONN Swap bit is set, it will be able to complete a VCONN Swap. If this bit is not set, then it will reject the VCONN Swap. 

    With regards to your PD3 compliance testing, it sounds like there may be a mismatch between the VIF and the configuration you have as the tester should not test a function that is not supported by the monitor.

    Thank you,
    Eric

  • 0 in reply to Eric Beljaars
    TI__Expert 4380 points

    Thanks Eric,

    In our test, when thh "Process Vconn swap" is enable, our PD would be able to detect Emark cable. However, when we uncheck the "Process Vconn swap", it could not detect the Emark cable and only process up to 20V 3A. In other words, if the "Process Vconn swap" is disabled, although the PD is configure at DRP and Power Source, it will not outptu 5V Vconn so could not detect Emark cable?

  • 0 in reply to Sai Loo
    TI__Mastermind 36751 points

    Hi SK,

    If you need to support E-marked cables, then it is required to enable the "Process VCONN Swap" bit. This would help you avoid the behavior you mentioned in your previous comment.

    Thank you,
    Eric