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ISO7760: Damage ISO devices under any input before power-supply?

Part Number: ISO7760


When there is no VCC power on ISO77xx/67xx and input High, is it possible to damage these devices?   My customer may occur any input before supplying power.  Please advise us.

Thanks and best regards,

  • Hi Hattori-san,

    Thank you for posting to E2E! ISO7760 and other digital isolator devices may be damaged if the input signal voltage levels exceed the power supply voltage levels. Therefore, it is not recommended to connect ISO7760 to input signals that are greater than its local power supply level by 0.5V, as stated in the Absolute Maximum Ratings of its datasheet (shown below).

    So if the power supply level is 0V, we recommend the input signal levels do not exceed 0V, and they should not exceed 0.5V to prevent permanent damage to the isolator. Please let us know if you or our customer have additional questions.

    Thank you,
    Manuel Chavez

  • Hi Hattori-san,

    As a follow up, isolator devices, including ISO7760, could support logic HIGH input voltage levels without Vcc present with the use of a failsafe logic buffer (e.g. SN74LV1G17, LVC1G125) at the isolator inputs (INx).

    Please let us know if this is a possibility for our customer or if there are further questions.

    Manuel Chavez