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MAX232: About the protection of Hot-Swap.

Guru 10385 points
Part Number: MAX232

Hi team,

I'd like to know about the protection of Hot-Swap.

What device would you recommend if we want to protect the input and output?
I think it needs for Overvoltage and Overcurrent.

Sincerely.
Kengo.

  • Kengo,

    I assume what you mean is more like hot plugin. The input is integrated with 5kOhm pull down, which might work with hot-swap. For the output pins, you can add some resistors (like 100Ohm) to limit the current. Also some engineer mentioned limiting the Vcc current with series resistor and big decoupling cap somehow works for overheating issue.

    Regards,

    Hao 

  • Hi Hao,

    Thank you for your reply.

    How about do you think about TVS diode for overvoltage?

    Sincerely.
    Kengo.


  • Kengo,

    The TVS diodes will work with fast voltage spikes by clamping them to a certain voltage level and shunting the power to ground, thus protecting the pin. Is this what you had in mind?

    Regards,

  • Hi Eric,

    Thank you for your reply.

    Yes.
    How do you recommend connecting the TVS diode?
    What kind of TVS diode(TI device) can be used?

    Sincerely.
    Kengo.

  • Kengo,

    Connecting diodes to clamp the voltages at the input and output pins is good practice if you're expecting fast high-voltage transients to occur on these pins. The type of diode you'll need to pick will be based on the operational and absolute maximum voltage ratings for that pin. The clamping voltage and breakdown voltage are important and key parameters to check when selecting TVS diodes.

    This article explains in detail how TVS diodes work and the important parameters to check when selecting them. Please let me know if you have any other questions.

    Regards,