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TPD12S521 HPD(HOTPLUG_DET_IN) 100K Ohm Resistors

dong jun choi
Prodigy 80 points
Other Parts Discussed in Thread: TPD12S521

Dear TI employee.


is Thera any particular reason 100K Ohm pull-up resistors as shown on the HPD_IN lines?
The Boardcom AP in HPD_IN has default pull down resistors on the inside.

If you have any question contact me anytime.

Thanks a lot

  • 0
    TI__Genius 12190 points
    Hello,

    The pull-down resistor in the Broadcom chip is to prevent a floating pin when there is no cable attached. The 100 kohm pull-up resistor for the TPD12S521 is needed to translate 5-V on HOTPLUG_DET_OUT to the VLV logic level required by the system, which could be 1 V_MIN to 5.5 V_MAX.
  • 0 in reply to Guy Yater
    Prodigy 80 points
    Hello, Guy

    Thank you for your reply.

    I didn't use Pull-Up resistor on HPD(Hot Plug Det)_In Line and Pull-down resistor on HPD_Out Line.
    Are we must to use Pull-Up resistor on HPD_In Line and Pull-down resistor on HPD_Out Line?

    is There often drain type HPD_In Pin on the inside?

    If you have any question contact me anytime.
    Thanks a lot.