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ISO1540-Q1: ISO1540-Q1 maximum ratings

Part Number: ISO1540-Q1
Other Parts Discussed in Thread: ISO1540, ISO1640


In the ISO1540-Q1 data sheet's absolute maximum table, it mentions that the SDA and SCL lines for either side should not exceed VDDx + 0.5V

So does that mean that the part may get damaged if the VDD is not powered and I2C activity is present on the same side?

  • Hi Kalhana,

    Thanks for posting to E2E! As mentioned in a similar thread linked below, damage is not expected to ISO1540 or ISO1640 devices when I2C activity is present on the SDAx and SCLx pins and a power supply is not present on Vccx pins. Since I2C does not drive data pins HIGH, ISO1540 and ISO1640 devices will not sink current so long as pull-up resistors -- as required by I2C -- are used on both data lines.

    Below is the similar thread:

    If you would also like assistance in selecting one of these two devices, we do recommend ISO1640 over ISO1540 since it includes newer technology, better performance specs, and higher isolation performance. Please let us know if there is additional information or assistance we can provide for you :)

    Thank you,
    Manuel Chavez