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Visitor II
November 2, 2020
Solved

ST25DV64K-IER6S3 load on I2C bus with VCC = 0

  • November 2, 2020
  • 3 replies
  • 694 views

Hi there

It seems that ST25DV64K-IER6S3 does not load the I2C bus even when there is no power on VCC. I have checked the datasheet but I have not found any information on that.

Could you confirm it?

BR

Gilberto

    This topic has been closed for replies.
    Best answer by JL. Lebon

    ​Hello Gilberto,

    Yes, no problem with that.

    The I2C outputs of ST25DV are open drain. This means they can only drive the signal low, and they can only drive it low when the VCC is active. With VCC=0, they will simply stays Hi-Z, not perturbating other i2c slaves.

    Best regards.

    3 replies

    ST Employee
    November 3, 2020

    ​Hello,

    What do you mean exactly by "load the bus" ?

    If the question is "is I2C active when vcc=0", the answer is no.

    Best regards.

    GErma.1Author
    Visitor II
    November 3, 2020

    Hi

    The i2c bus has an accelerometer, an st25dv and a temperature sensor on it . Can the cpu communicate with these others devices when the ST25DV vcc is 0?

    BR

    Gilberto

    JL. LebonAnswer
    ST Employee
    November 3, 2020

    ​Hello Gilberto,

    Yes, no problem with that.

    The I2C outputs of ST25DV are open drain. This means they can only drive the signal low, and they can only drive it low when the VCC is active. With VCC=0, they will simply stays Hi-Z, not perturbating other i2c slaves.

    Best regards.