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Original question:

TPS6594-Q1: using VIO_IN at 1.8V

TPS6594-Q1: I2C pullup to 1.8V when VIO is supplied with 3.3V

josh dong
Prodigy 50 points
Part Number: TPS6594-Q1
Other Parts Discussed in Thread: TDA4VH,

Tool/software:

Hello TI experts,
I am using the TPS6594133A with the TDA4VH. The TDA4VH's MCU_IO is supplied with 1.8V. I noticed in the TPS6594 datasheet that its VIH(DIG) and VIL(DIG) are compatible with 1.8V logic levels. Could the I2C interface of the TPS6594 can be directly connected to the MCU's 1.8V IO of the TDA4VH without using a level shifter?

  • 0
    TI__Genius 13850 points

    Hi Josh,

    In principal yes but that would require PMIC VIO to be supplied 1.8 V as well. On system level I'm not sure if this is possible with TPS6594133A-Q1 device. 

    Since VIO can be used for other purposes to control external resources 1.8 V might not be high enough. 

    So if original reference design is using level shifter there has to be some reason why it is done so.

    Br, Jari

  • 0 in reply to Jari Niemela13
    Prodigy 50 points

    Thank you for your reply. Actually, I want to know if using VIO = 3.3V while pulling the TPS6594-Q1's I2C interface with 1.8V pull-ups would still satisfy the VIH and VIL thresholds of the TPS6594-Q1's I2C interface.The datasheet does not specify that the I2C interface levels must meet VIH > 0.7 × VIO and VIL < 0.3 × VIO.

  • +1 in reply to josh dong
    TI__Genius 13850 points

    Hi Josh,

    That seems to be right. Reason being input direction is always referenced to internal LDO 1.8 V level.

    Br, Jari