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TMDS181: Pull up and pull down resistor for control pins

Kawai
Guru 19775 points
Part Number: TMDS181
Other Parts Discussed in Thread: TMDS171

Hello Team,

Please allow me to ask you about the pull-up and pull-down resistor value for TMDS181 control pins. I see below table in the datasheet.

It says, "Control pin MIN/MAX voltage for High/Low".

[Q1] Does this mean that the pull up or pull down resistor value must be smaller than 65k ohm ?

[Q2] What happens when user uses 68k ohm ?

[Q3] What happens when user uses 10k ohm ?

Best Regards,

Kawai

  • 0
    TI__Mastermind 23815 points

    Hi Kawai-san,

    Control pins were designed using 65k pull-up/pull-down values around it will work fine, 68k is close enough.

    10k is too low; it may cause the device to lose its configuration.

    Regards

  • 0 in reply to Moises Garcia
    Guru 19775 points

    Hello Moises-san,

    Please allow me to double check for each cases.

    Pull-Up
    Q1). What is the required accuracy for the 68k pull up resistor ? I believe it must be in certain range of 65k ohm.

    Pull-Down
    Q2) What is the required accuracy for the 68k pull down resistor ?

    Q3). I believe pull down could be a smaller resistance. Is 10k or 1k pull down acceptable ?

    Best Regards,
    Kawai

  • 0 in reply to Kawai
    TI__Mastermind 23815 points
    Hi Kawai-san,

    These are the resistors values that will make DP149, DP159, TMDS171, and TMDS181 work properly.

    [3-Level Input pins]
    Pull-up: 65k +/- 10%
    Pull-down: 0 to 65k + 10%

    [2-Level (LVCMOS) Input pins]
    Pull-up: 0 to 65k + 10%
    Pull-down: 0 to 65k + 10%

    keep the nominal resistor value + the tolerance within the ranges above.

    Regards
  • 0 in reply to Moises Garcia
    Guru 19775 points
    Hi Moises-san,

    Thank you so much for your prompt support.

    Best Regards,
    Kawai