Fail safe feature of ADM3485EARZ


      We would like to confirm the Fail safe feature of ADM3485EARZ.

      and have two questions as below


      1  In the data sheet of ADM34858EARZ,  it is with fail-safe feature.

          But it do not present the voltage range of fail-safe.

          We see AN-960(Implementation Guide)  shows the fail-safe range of differential input threshold voltage

          is -30mV to -200mV.    Is ADM34858EARZ with the fail-safe range of differential input threshold voltage?

  2.   In AN-960, New generation RS-485 transceivers have an improved feature that includes true fail-safe receiver inputs.

        This eliminates the need for pull-up/pull-down resistors.

        Our original circuit is with 330 ohm pull high and pull low resistor(Let the differential voltage between A and B is 500mV when the differential output is open)

         Due to the 330 ohm cause a Main chip boot problem.      We would like to remove the 330 ohm pull high and pull low resistor.     

         Please help to confirm if ADM3485EARZ chip is with true fail-safe feature and removing 330 ohm is OK.


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