From the datasheet, I see there are steering diodes in the part that protect against over-voltage transients. I am in an application where the diferential TX and RX lines must survive a 50V, ~300us transient.
If I use a TVS with a withstanding voltage of 5V and a clamping voltage of ~9V then 10s of mA will run through the steering diodes even if I place 100 ohm resistors in series with the pin inputs. (9-5.5V)/100 = 35mA. It's likely that adding a 100ohm resistor after a 120 ohm termination resistor only works on the TX side, as changing the source impedance on the RX line may be problematic.
What kinds of currents can the steering diode handle and for how long?
