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MAX3243: RS232C channels

FRANK1
Expert 8205 points
Part Number: MAX3243

Hi sir,

Can the MAX3243IPW use on two RS232C channels?

Thanks.

Regards,

M

  • 0
    TI__Guru 62920 points

    Yes, it is OK to use the device this way.  You could leave unused ROUT, RIN, and DOUT pins disconnected and tie unused DIN ports either to VCC or GND.  Note that 2 TX /2 RX devices are available as well (for example, TRX3232E), so you may consider one of these devices as well if you do not want to have unused channels.

    Regards,
    Max

  • 0 in reply to Miguel Robertson
    TI__Expert 8205 points

    Hi Max,

    Thank you for your response.

    Could you tell me if there are notes on using two RS232C?

    Moreover, I have two further inquiries,

    Could you confirm it?

    1.Auto power down function

    Set force on = [low], force off = [high] in the schematic,

    Auto power down enabled,

    Can I also use this feature when using two RS232C systems?

    2.

    RIN is unused,

    I do not make this RIN floating, I set it to low.

    Is there no problem with this operation?

    Thanks a lot.

    Regards,

    Frank

  • 0 in reply to Miguel Robertson
    TI__Expert 8205 points

    Hi Max,

    Is there any update on my further inquiries ?

    Thanks a lot.

  • 0 in reply to FRANK1
    TI__Guru 62920 points

    Sorry for the delay - I wrote a response but for some reason it doesn't seem to have posted.

    Auto powerdown would work with two independent RS-232 interfaces.  It would just require that both interfaces are inactive before it would transition to the powerdown mode.  (The function works by detecting whether an invalid voltage level is present across all RIN input ports on the device.)

    It is OK to tie unused RIN ports to GND.  This is functionally similar to leaving them floating since each port has an internal 5-kOhm pull-down resistance.

    I don't know of any other issues related to using a single transceiver for multiple RS-232 ports.  If you can think of any specific concerns, though, I am happy to help answer them.

    Regards,
    Max