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DAC6574: Digital input tolerant

NAOKI AOYAMA
Guru 11215 points
Part Number: DAC6574

Hello,

Our customer use the DAC6574.

They refer to the Absolute Maximum Ratings, have a question.

It is mentioned the Digital input voltage to GND up to VDD+0.3V.

Is this correct?

They use some devices with same I2C bus. They want to turn off the power individually.

If there is limit at Digital input, they can not use the DAC6574.

Best Regards,

Naoki Aoyama

  • 0
    TI__Guru 53433 points
    Hi Aoyama-san,

    In the case where the DAC is powered off but the I2C bus is still in use, they will be technically violating the abs. max conditions. I2C pins of the DAC will essentially look like diodes to ground (due to the ESD cells on the pins). These will become active when the voltage of the pins exceeds ~0.7V, which will probably disrupt the I2C communication for other devices. Some series resistance may help isolate the DAC from the bus, but it will also change the logic high and low voltages. I recommend a I2C buffer with an enable pin if they are planning to implement this configuration.

    Thanks,
    Paul
  • 0 in reply to Paul_Frost
    Guru 11215 points
    Hello Paul-san,

    Thank you for your reply.
    I see.
    I will suggest the customer to use I2C buffer as the TCA980x.

    Thanks,
    Naoki Aoyama