A powered USB hub has it's own power brick.
I haven't heard of any that use a USB Y cable but I never looked for one either.
This is the one I have.
Amazon.com: Asus 8X External Slim DVD+/-RW Drive SDRW-08D2S-U - Retail (Black): Computers & Accessories
They say it can work off only one of the USB plugs, but I have never gotten to work unless both are connected.