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TS3DV642: Video LVDS signal 2:1

Shuji Ishiwata
Mastermind 8820 points

Part Number: TS3DV642

Tool/software:

Hi All,


I have a question about the TS3DV642.

I'm inputting video LVDS signals to sides A and B, then selecting and outputting them from side D.

Is a 100 Ω termination resistor necessary on sides A and B?


Best Regards,
Ishiwata

  • 0
    TI__Genius 11865 points

    Hi Ishiwata,

    Termination at the LVDS receiver is essential for proper LVDS communication. However, it sounds like in this case, you are using sides A&B to pass the LVDS driver signal. If this is the case, you would only need the termination resistor on the receiver end.

    Best,
    Katy

  • 0 in reply to Katy West
    Mastermind 8820 points

    Hi Katy,

    Thank you for your answer.

    I understand that since the receiver is connected to the D side, a termination resistor is required on the receiver side. Is this correct?

    I also understand that therefore no termination resistor is required on the input side (A side and B side) of the TS3DV642.

    Is my understanding correct?

    Best Regards,
    Ishiwata

  • 0 in reply to Shuji Ishiwata
    TI__Genius 11865 points

    Hi Ishiwata,

    From reading about the LVDS spec, that is my understanding!

    Best,
    Katy

  • 0 in reply to Katy West
    Mastermind 8820 points

    Hi Katy,

    Thank you for your answer.


    I have an additional question. Is it okay to set the following unused pins as follows?
      CEC_A/B: 10kΩ pull-down
      CEC: NC
      HPD_A/B: 10kΩ pull-down
      HPD: NC
      SDA_A/B: 2.2kΩ pull-up (5V)
      SDA: NC
      SCL_A/B: 2.2kΩ pull-up (5V)
      SCL: NC

    Also, is it okay to leave the unused D+/- pins NC?

    Best Regards,
    Ishiwata

  • 0 in reply to Shuji Ishiwata
    TI__Genius 11865 points

    Hi Shuji,

    If your application runs at a low frequency, that is ok! Otherwise, at higher frequencies, I would suggest adding a 50ohm pull down to ground on the unused pins. This is to mitigate the possibility of noise coupling. See this FAQ for more details on what to do with unused pins.

    Best,
    Katy