TPS65982: TPS65982

Part Number: TPS65982
Other Parts Discussed in Thread: TPS65987D

Tool/software:

Hi,

I am currently learning the basic knowledge of Type-C PD and I have some questions about USB PD alternate mode negotiation scope as the picture shown.

Question:

  1. What is the PP_HV?  Why does its waveform look like this?
  2. Is the waveform on CC pin is a square wave during the negotiation?
  3. What is the difference between DP negotiation and TBT negotiation?

Thanks.

Regards,

Thomas

  • Hi Thomas,

    Thanks for reaching out on E2E!

    What is the PP_HV?  Why does its waveform look like this?

    PPHV is the high voltage power path going into the PD to source out or it becomes the power being sinked into the system.

    The reason we see PPHV rise from 0V to 20V is because the PD contract negotiated is complete which allows us to close the switch that allows power to go into the system.

    Is the waveform on CC pin is a square wave during the negotiation?

    The CC lines are what are used to communicate PD traffic. You can use a PD analyzer to decode this traffic.

    What is the difference between DP negotiation and TBT negotiation?

    These are different alternate modes that are entered depending on what is supported by the DFP and UFP.

    For basic PD questions, I highly reccomend you take a look at the app notes in the TPS65987D product page!

    Thank you,

    Kevin