What this dual RS422/RS485 line driver is for
It provides two differential outputs with no integrated receiver — this is a pure driver, not a transceiver. Typical applications include industrial control backplanes, point-to-point data links, and differential signalling over twisted-pair cables where the receiver is handled by a separate part like the UA9637 or SN75175.
That rules out 3.3 V-only buses — if your system runs on a 3.3 V supply, this driver needs a separate 5 V rail or a level shifter. UA9638CDR) would be needed.
Package and mounting — board-level fit
No exposed thermal pad — dissipation is through the leads and board copper, adequate for this driver's typical output current.