ADUM5401 Schematic Review

Hello,

Attached is isolator design by using ADI ADUM5401.

Could you help to check whether this interface between ADUM5401 and TI TRS3221E( For RS232) and TI SN65HVD72D( For RS485) correct?

Please recommend me the maximum worse case voltage/current threshold that the RS485 lines of this chip (RS485_D+ and RS485_D-) can handle on the positive and negative sides? I prefer not to use any protection diodes externally.

Please also recommend any analysis and interface using ADuM5401 to provide isolated RS232/485 interface re-using the same circuit?

  • 0
    •  Analog Employees 
    on Jun 13, 2014 7:41 PM

    wcgood:

    I support the ADuM5401 and I reviewed the interface between the ADuM5401 and the TI TRS3221E (RS232) and the TI SN65HVD72D (RS485).  I observed that it may be possible to have both the RS232 and RS485 outputs on at the same time, so I recommend that you review the current required by the RS232 and RS485 from the VISO 3.3V provided by the ADuM5401, which is limited to a maximum of 60mA.

    As far as your questions about the "maximum worse case voltage/current threshold that the RS485 lines of this chip (RS485_D+ and RS485_D-) can handle on the positive and negative sides?" and "Please also recommend any analysis and interface using ADuM5401 to provide isolated RS232/485 interface re-using the same circuit?"  I have asked our application engineering group who support RS485 to contact you directly by email.

    Regards, Brian