RS485 Functionality difference
all are same but difference in functionality


Huh? what does it even mean? They all are RS-485 transceivers, so their functionality is exactly the same, except ADM2483 provides additional isolation function.

MAX485 is not slew limited. It is pretty regular one unit load (up to 32 receivers) 2.5Mbps transceiver. 

SN75176A is also one unit load but faster 5Mbps transceiver. SN75176B is even faster at 10Mbps.

ADM2483 is slew-limited and isolated 1/8 load transceiver. Up to 256 receivers at 500 kbps.