File talk:Mitsumi 348A.jpg
Why Microchip?
Manufacturer is MITSUMI, not Microchip.
For Example: http://www.utsource.net/ic-datasheet/MM1024A-1766443.html
http://www.marjorie.de/kawai/kawai22.htm
I was checked service manuals for COK001, voltage regulators labeled with same letter are ICs manufactured by Mitsumi.
It was labeled as microchip because the logo is very similar (most microchip ic's has a circle aroung the "M" but there are some that doesnt), but i think you are right, mitsumi sounds about right because:
There are other IC's in the PS3 motherboard manufactured by mitsumi
Microchip is a corporation too big for supplying small ic's to sony... sony could use any other cheap manufacturer (like mitsumi)
There are photos in internet of mitsumi ic's with the logo and looks exactly like the logo used in ps3 ic's
There is no datasheet from mitsuni matching the model 348 or 463 though http://www.mitsumi.co.jp/latest/Catalog/indexuse/index_e.html