• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Subscribers 32 subscribers
  • Views 844 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

SN75DP139 Display Port

Mehrdad Bradaran
Intellectual 430 points

Other Parts Discussed in Thread: SN75DP139

Hello,

Can you please help with the following?

1) Is there a reference design available for this device?

2) How does pin20, DP source provide power?

3) Why DP++ graphic card source does not list 4K resolution format?  The display/SINK EDID does advertise UHD-4K/30Hz capability.

Please advise.

Thanks,

Mehrdad.

  • 0
    TI__Mastermind 23815 points
    Hi Mehrdad,

    1) I will provide reference schematic by email.
    2) From source side, Pin20 is 3.3V 500mA, you can power up DP139 using this power supply.
    3) Could you please elaborate about this question?

    Regards
  • 0 in reply to Moises Garcia
    Intellectual 430 points
    Hi Moises,

    The customer replied back:

    "Is there special conditions or sequence to get the DP++ to output +3.3V on Pin 20? Surface Book and Apple Laptops sometime supply the +3.3V and sometime not (Mostly does not).

    I have a PC DP++ graphic card, when I connected to the DP++ output interface port directly to the DP monitor input port, the graphic card can display UHD/4K resolution format without issue. The resolution selection listed the UHD/4K as default/recommended. This shows the graphic card is capable of outputting UHD/4K resolution. When the DP++ interface is connected through the SN75DP139 via the monitor HDMI input port, the resolution selection from the graphic card is limited to 1080p60 resolution only. I want to know why the DP++ from the Intel graphic card driver limits the resolution to 1080p60."

    Please advise.

    Thanks,

    Mehrdad.
  • 0 in reply to Mehrdad Bradaran
    TI__Mastermind 23815 points
    Hi Mehrdad,

    DP_PWR should be provided when outputs are enabled.
    For these power saving devices, they may enable PD_PWR only when needed, verify they have Pin19 to gnd.
    Check if PD_PWR is enabled when HPD is high.
    PD_PWR is enabled when a connection is established?

    Issue in detecting all capable resolutions may be in AUX channel. could they provide schematic for review?

    Regards
  • 0 in reply to Moises Garcia
    Intellectual 430 points
    Hello Moises,

    I will email you the DP adapter schematic.

    These were verified:

    1) Pin 19 is connected to ground.
    2) I did force the HPD to always ‘ON’ without resolve. Original design was for HPD to enabled only when ‘PD_PWR’ is detected as active or ‘ON’.

    Can you please explain "The “PD_PWR is enabled when a connection is established?“.

    Also would you be able to send me the DP1.3 specifications?

    Thanks,
    Mehrdad.
  • 0 in reply to Mehrdad Bradaran
    TI__Mastermind 23815 points
    Hi Mehrdad,

    In the tests you have run, PD_PWR is available when source is transmitting video or when not transmitting video?
    Since PD_PWR is a source signal, we can't provide more support on it, the devices we have tested have PD_PWR always available.

    We don't have specification for DP1.3.

    To debug the resolution listing issue,
    they could connect directly from source to sink and see if there is any difference
    Monitor DDC channel to verify this resolution is being read.
    Verify GPU supports this resolution in DP++ mode, you said it works when connecting to DP port in monitor, but sometimes GPU doesn't support the same resolutions in DP++ mode.

    Regards