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TPS65988: I2C pull-up domain

Part Number: TPS65988


Hi,

Considering the case that I2C1 is connected to EC and I2C2 is connceted to TBT, can we pull up the I2C signals (including IRQ) to the 3.3V of EC and TBT respectively?  Is there any concern if I2C is not pulled up to VIN_3V3 or LDO_3V3?

THanks!

Antony

  • Hi Antony,

    It is suggested that the I2C lines are pulled up to LDO_3V3 of the PD controller. This would ensure that any I2C traffic sent during dead battery operation is not lost.

    If this answers your question, PLEASE select This resolved my issue

    Thank you,
    Eric

  • Hi Eric,

    The situation we have now is, this specific system does not support either PD sink path or dead batery mode.  With I2C pulled up to LDO_3V3, customer is afraid of current leakage from LDO_3V3 to their EC (I2C host) through I2C signals when a PD source is connected to the type-c port when this system is not powered up.

    So, considering the case of not supporting dead battery mode, can we add I2C pull-up at either VIN_3V3 or the 3.3V of I2C host device (e.g. EC, TBT)?

    Thanks!

    Antony

  • Hi Antony,

    For this application it should be okay. The main requirement is to ensure the I2C lines are pulled-up before any I2C communication begins.

    If this answers your question, PLEASE select This resolved my issue

    Thank you,
    Eric