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ADS1013 communicate with 1.8V I2C

K.Hamamoto
Guru 12155 points
Other Parts Discussed in Thread: ADS1013, PCA9306

Hi

I have a question about I2C interface of ADS1013.

ADS1013 has I2C interface and VDD supply is 2V to 5.5V.

Can this device communicate with 1.8V I2C interface if VDD of ADS1013 is 2V? Because the input logic threshold is defined as the following,

If VDD is 2V, VIH=1.4V and VIL=0.6V.

Regards,

Koji Hamamoto 

  • 0
    TI__Guru** 113765 points

    Hi Koji,

    The ADS1013 does require that the minimum supply voltage be 2.0 V.  However you are correct about the I2C interface and the VIH and VIL requirements.  The I2C interface is open drain on the ADS1013 and should be able to handle the lower pull-up voltage using the specified voltage ranges.

    If there is any doubt, a level translator could be used such as the PCA9306.

    Best regards,

    Bob B

  • 0 in reply to Bob Benjamin
    Guru 12155 points
    Hi Bob,

    Thank you for your support.

    I think it is possible to communicate with 1.8V interface when the VDD of ADS1013 is connected to 2.0V.
    (The VOH and VOL of 1.8V interface signal should be followed the VIH/VIL of ADS1013 specification.)

    On the other hands, I concerns the sequence of the supplies which are power supply of ADS1013(2.0V) and external pull up supply(1.8V) .
    Do you think there is any sequence for these power supply?

    Regards,
    Koji Hamamoto
  • 0 in reply to K.Hamamoto
    TI__Guru** 113765 points

    Hi Koji,

    If both supplies ramp at the same time there should not be a sequencing issue.  If there are concerns it would be best to apply the 2.0V source first.

    Best regards,

    Bob B