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TLK2711-SP: input control pins current and pull up

assaf matia
Prodigy 240 points

Part Number: TLK2711-SP

Hi,

In the datasheet for pin ENABLE (and some others) it is written that it has internal pullup of 10K (page 5 note 1), but in the Iil (Current input Low) parameter in the  TTL Input Electrical Characteristics chapter 7.5 table, it is written that if the input pin is 0.4V the current is -40uA . it is not make sense because if there is internal pull up of 10K the current should be about (2.7-0.4)/10K=0.23mA.

what I am missing here?

  • 0
    TI__Guru 62930 points

    Assaf,

    I am uncertain why these are labeled as a resistive 10K pullup in the notes. 

    They are implemented as current sources in the input macros. 

    The limits in the IIH/IIL specifications are correct (+/-40uA)  These are fairly weak pullup/down sources.   Realistically, these would be more equivalent to a 100K ohm pullup/downs.

    The verbiage for pullup/down note will be put in queue to be updated on next release.

    If this answers your question, please click "This Resolved My Issue"
    Regards,
    Wade

  • 0 in reply to Wade Vonbergen
    Prodigy 240 points

    Wade Vonbergen said:

    Assaf,

    I am uncertain why these are labeled as a resistive 10K pullup in the notes. 

    They are implemented as current sources in the input macros. 

    The limits in the IIH/IIL specifications are correct (+/-40uA)  These are fairly weak pullup/down sources.   Realistically, these would be more equivalent to a 100K ohm pullup/downs.

    The verbiage for pullup/down note will be put in queue to be updated on next release.

    If this answers your question, please click "This Resolved My Issue"
    Regards,
    Wade