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Mux for Displayport 1.2 multi-mode signals

Gunter
Prodigy 30 points
Other Parts Discussed in Thread: TS3DV642, HD3SS214, HD3SS215

Hey,


we need to switch three DP++ sources onto one sink (display) and we are not sure what would be the right mux. I found out there are HD3SS214, HD3SS215 and TS3DV642 that are fast enough for the displayport-dual-monitor capability or 4K video. We want the ability to use active and passive adapter-cables to convert to HDMI or DVI, as it ist possible with the normal DP output of the graphics card. As far as I know, the graphics card would switch from LVDS mode to TMDS, if it detects a passive DP-to-HDMI adaptor, so the mux needs to pass theese signals transparent to the source.


Tanks for any help with that problem. We are not really into DP and HDMI, so we have a lot to study there.

  • 0
    TI__Mastermind 45575 points
    Gunter,

    The HD3SS214, HD3SS215 and TS3DV642 are passive switches with no buffereing or current drive capability. Their signal path can ideally be modeled as 0 ohm wires and you can use the parasitic impedances (Ron and Con) characterized in the datasheet to get more accurate models.

    What ever signal you put on one side of the FET will pass through to the other side with little distortion. You can place these switches in your signal path and they will not have any effect on the digital signal's protocol.

    Let me know if you have other questions.
    Adam
  • 0 in reply to Adam Torma
    Prodigy 30 points
    Thanks Adam,

    then we could use all these switches. That sounds good!
    What is the advantage of using the HD3SS215 over the TS3DV642 for an application with two DP++ sources? HD3SS215 can switch DDC lines , but I think that is not needed (only if one uses HDMI).
    Am I correct that wie need to route the config1 and 2 pins manually (via T3USB3000) from sink to the two sources? So the 8 datalines, aux+/-, HPD are routed via p.ex. TS3DV642 and config1+2 are routed via T3USB3000. DP_PWR (pin 20 at DP-connector) doesn't need to be connected, because it is possible to permanently apply the power to adaptor or display via voltage regulator.

    I hope I got everything right. Thanks in advance for answering these questions. Never worked with DP before...
  • 0 in reply to Gunter
    TI__Mastermind 45575 points

    Gunter,

    I believe the TS3DV642 to be a high performing part for its lower power consumption and 1.8 V compatible digital logic but the HD3SS215 can come in a smaller package.  The HD3SS215 also has one additional 1:2 signal path compared to the TS3DV642.

    I'm not sure I understand you additional questions.  Could you draw a diagram to help illustrate what you are asking?  I'm also going to move this thread to the consumer and computing forum and see if any of those engineers have some comments as well.  

    Thank you,

    Adam  

  • 0 in reply to Adam Torma
    TI__Mastermind 23815 points
    Hi Gunter,

    You are right, CONFIG1(CAD) and CONFIG2(CEC) need to be routed separately.
    Could you elaborate about this application, is this part of a monitor or TV?
    Why there are three DP++ sources and one sink, sink is DP or HDMI?

    Regards
  • 0 in reply to Moises Garcia
    Prodigy 30 points

    Hi Moises Cracio,

    we got three DP++ sources and one Monitor. That is used in an industrial application with three computers that can be switched to one display. Currently we are using DP displays, but depending on the prices we want to be able to switch to HDMI or DVI with only using a passive adaptor.


    Thanks so far,
    Gunter

  • 0 in reply to Gunter
    TI__Mastermind 23815 points

    Hi Gunter,

    In this case you may not need CEC, this is a pin to control several multimedia devices using one TV remote control example.

    You may not need a switch for CAD, you could connect CAD_SINK to the three DP++ source ports, HD3SS215 has a switch for HPD and only the source with HPD asserted will send video.

    Regards