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ADM3485's differential input threshold voltage vs input frequency

Question asked by moto on Aug 24, 2015
Latest reply on Aug 25, 2015 by moto


I would like to know about the Differential input threshold voltage of RS-485 receiver.

It should be -0.2V/+0.2V


Does it depend on the signal frequency?


I checked ADM3485 by 5MHz square wave, then it needs over 0.8V amplitude.

(When it inputs the sine wave, then it needs over 1V amplitude)

The duty is 50%.

At 200KHz, the threshold is about +/- 0.2V.


Does this feature meet the RS485 specifications?


The input level will change the delay time?


How to measure this threshold?


Could I have the advice?