The UCC3829DW-1: This is a switching controller, the PWM control core for isolated or non-isolated DC-DC converters, not a complete regulator module — the external power stage (MOSFET, transformer, feedback loop) defines the output rail.
Package and procurement reality
Supplied in Bulk — tube or tray, not tape-and-reel — which matters if your pick-and-place line expects embossed carrier; a tube-fed feeder or manual placement is the alternative.