On Wed, 29 Sep 2010 16:07:30 +0100, "N_Cook"
wrote:

BNOAA or BN0AA, B at start not 8, probably DC-DC converter, any knowledge?

The first step in identifying the part is to identify the package.
Digikey lists over a dozen 8 pin SMD packages. Even the SOIC-8 comes
in a variety of widths. The next step is to Google the package,
marking code and the actual marking code - like this:
SOIC-8 marking code BNOAA