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ISO1640: ISO1640 Diode question

Part Number: ISO1640

Hi Team,

I check that the ISO1640 has a diode on the side 1 because of the bi-direction function need. But why we don't have one diode on the side 2?

Besides, is the Vref also needed in side 2?

Thank you.

Frank

  • Hi Frank,

    Thanks for reaching out.

    Please refer to section 8.5 of ISO1640 datasheet that describes the device working principle briefly and also the reason for using a diode and a comparator on Side1. I am copying below a snippet from datasheet for your quick reference.

    I check that the ISO1640 has a diode on the side 1 because of the bi-direction function need. But why we don't have one diode on the side 2?

    As stated in the datasheet snippet shown above, not having a diode and comparator will lead to a closed loop caused by back-to-back connection of the two unidirectional internal channels to form a single bidirectional channel. To break such a closed loop, the diode and comparator are used and you only have to break the loop once either on Side1 or on Side2. There is no need to add the didoe and comparator on both sides.

    Besides, is the Vref also needed in side 2?

    VREF creates a hysteresis to the comparator and is only needed once on the side where a diode is used.

    I hope this addresses your questions and provides clarification. Thanks.


    Regards,
    Koteshwar Rao