The input amplitude dependency of ADM3078E propagation delay


RS485 receiver should operate by +/- 200mV differential signal.

ADM3078E receiver spec defined the delay time by +/- 1V input.

Could you show us the propagation delay at +/- 200mV input?

How about input amplitude dependency?



  • Hi Moto,

    At what data rate are you operating the ADM3078E ?

    Are you operating the part at less than 16 Mbps ?

    Are you expecting to see a bus differential voltage of +/-200 mV in your application?

    You would need to be using a very long cable >1 km to see a +/- 200 mV bus differential in an application.

    Best Regards,


  • Hi Moto,

    There is a trade off for data rate vs. differential input voltage amplitude vs. propagation delay.

    The device performance will be similar to, or better than, competitor parts.

    I do not have access to this information.

    I will need to perform this measurement in the lab.

    However, you would not see 16Mbps at +/-200 mV in a real application.

    So I would like to know why you are asking this question?



  • Hi Richard

    Thank you very much for your reply.

    I would like to know about ADM3078 feature, not about RS485 feature.

    I know low input level makes big propagation delay at ADI devices.

    I would like to see that data.



  • Richard

    Thank you for your support.

    I know I can't see 16Mbps at +/- 200mV.

    I want to see the performance of this device, the limit speed vs input level.

    But I see ADI can't show that data.