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HERCULES_SAFETY_MCU_DEMOS: RM44L520APZT

Denise George
Prodigy 20 points

Part Number: HERCULES_SAFETY_MCU_DEMOS

Hello,

What is the silicon resistor value, in Ohms, used in the RM44L520AAPZ for the I/O Pin as internal pull-ups or pull-downs?

Also can you send a schematic / Block diagram of the I/O pin?

In the MSP430F series, it was 20K at ambient (25C).  I am looking for a similar answer.

Thanks and best regards,

Denise

  • 0
    TI__Mastermind 21425 points
    Hi Denise George,
    In fact this pull-up/down is not a resistor (resistor is not easy to be implemented in silicon). Pull-up/down is actually a current source in this case. That is why current is specified. Depending on Vccio equivalent resistance could be calculated. In recommended operating conditions is stated that nominal value of Vccio is 3.3V . In that case equivalent resistance for 20uA pull up/down will be 165kOhm and for 100uA - 33kOhm.

    Best regards,
    Miro
  • 0 in reply to Miro
    TI__Mastermind 49120 points
    Please also note the range for the pull currents specified. The 20uA typical pull has a min value of 5uA and a max value of 40uA. The 100uA typical pull has a min value of 40uA and a max value of 195uA.

    Regards,
    Sunil
  • 0 in reply to Sunil Oak
    Prodigy 20 points

    Thank you for your comments.

    Yes, I did read the data sheet and was able to back calculate the resistance based on the pull-up current strength, which I can then use to apply for a worst case for analysis over the full temperature range of the device.

    I just wanted a resistance value for the silicon resistor as was done with the MSP430F family, not a current strength estimate that I had to use to calculate the resistance by hand.

    The question is resolved.  Thanks again.