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TCA6424A: TCA6424ARGJR

Part Number: TCA6424A

Hi Team

I am using TCA6424ARGJR Expander.

I have Connected VCCP = 3.3V, VCCI = 3.3V (same supply). As all the 3.3V level GPIOs of SoC are used, I am left with only 1.8V level pins. As INTn (Pin 32) is defined as an open drain output pin in the TCA6424ARGJR datasheet, it has been Pulled up to 1.8V level of the SoC. However, as per the TCA6424ARGJR datasheet recommendation, INTn (Pin 32) has to be pulled up to VCCI (Page 4). Is it fine to pull the INTn Pin to different voltage (1.8V) which is different from the VCCI voltage? Kindly confirm if this is okay.

Thanks & Regards

Rekha

  • Section 8.4.3 of the datasheet says:

    The INT output has an open-drain structure and requires pullup resistor to VCCP or VCCI depending on the application.

    An open-drain output can be connected to any voltage. The device does not measure the high voltage; it does not make any difference if it is VCCP or VCCI or something else.