[RS-485] (+24V) convolution to RS-485 line


I would like to know we have solution or not for the customer's question.

The customer willing to use ADM483. And they want to SUPERIMPOSING DC (+24V) on RS-485 half duplex line.

(And also separate DC and data after receive)

Is there anything solution that we have?

Actually, some video transmit equipment have such a function like as Power over Ethernet.

(example product as below)

B&H Photo Video

Thank you for your help as always.

Best regards,


  • 0
    •  Analog Employees 
    on Apr 8, 2016 9:38 AM

    Hi Sofy,

    The ADM483 has a Standard RS-485 A, B input common mode voltage range of -7V to +12 V.

    The absolute maximum (DC) rating on the A,B pins is –9 V to +14 V.

    Adding 24 V DC to the ADM483 A,B bus pins would not be possible.

    Best regards,


  • 0
    •  Analog Employees 
    on Apr 11, 2016 5:30 AM

    Hello, Richard,

    Thank you for your response!

    I understood that.

    Mostly ADI parts cover -7V to +12V that I've checked on web also.

    And also notice about A, B pins absolute maximum DC (up to +14V).  

    Best regards,