On Fri, 8 Feb 2013 12:29:43 +0000, juanvivo
put finger to keyboard and composed:

U16: 54331 97M AOXR
'Converter (Integrated Switch) - Step-Down (Buck) Converter - TPS54331 -
TI.com' (http://www.ti.com/product/tps54331)

U16 is a PWM controller with integrated MOSFET chopper:
http://www.ti.com/lit/ds/symlink/tps54331.pdf

The application circuit on page 11 of the datasheet shows an external
Schottky flywheel diode. The part number (B340A) matches the markings
on D7.

AFAICT, this would constitute the +5V buck converter.

U17 : 4407 DA9S1E
http://pinout-circuits-images.dz863.com/120/AF4407.jpg

It looks like U17 is a P-channel MOSFET. Normally in that position I
would expect it to be functioning as an external chopper for one of
the buck converters. However U16 has its own internal chopper. Is it
possible that U17 provides additional current for U16?

U14: TPS or PS 53124 TI 96K DQ4C . I´m nor sure with the "T"
searching...

It appears that U14 controls two buck coverters (+1.8V and +3.3V):
http://www.tij.co.jp/jp/lit/ds/symlink/tps53124.pdf

"The TPS53124 is a dual, Adaptive on-time DCAP mode synchronous
controller."

There is a typical application diagram on the first page of the
datasheet.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.