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    Protect RS485 bus from overvoltage(24V)

    I used PSM712 and PSD12C with 2 resettable fuses(100mA,60V) at output pins(A,B) of RS485 driver IC(ADM485) but these comabination can not protect
    driver IC from failure when high voltage (for example 24V) is applied to A ,B and GND lines.

    Please help me to design a circuit that is reliable when high voltage is applied to it by mistake in wiring.

    •   Alt15th October 2012, 16:52

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    Re: Protect RS485 bus from overvoltage(24V)

    Use trans-orbs and/or zenner diodes.



    •   Alt15th October 2012, 18:37

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  3. #3
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    Re: Protect RS485 bus from overvoltage(24V)

    PSM712 ans PSD12C are RS485 TVS,but ADM485 will fail if we apply 24V between A,B,GND.

    Is there any tested circuit ?

    There are IC from linear that is +-60VDC tolerant ,but the price is 4 times the ADM485!!!



    •   Alt15th October 2012, 20:18

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  4. #4
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    Re: Protect RS485 bus from overvoltage(24V)

    no experience? no help?

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    no experience? no help?



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