The Linear Technology High Efficiency, Synchronous, 4 -Switch Buck-Boost Controller is a very sophisticated voltage regulator capable of regulating an output voltage to 1% from an input voltage range of 4V to 38V that can be above or below the output voltage. Mine has a week 25 2011 date code.
As an aside, I originally create significantly higher resolution images than what I am able to post. I cannot post images above ~10MB without getting an upload error. This seems to be a limitation related to WordPress and my web host. I have tried all sorts of work arounds to no avail.
The part is made on a two metal fairly modern Bipolar process. Designed in 2009, here is a link to the datasheet and the block diagram for the partIts a pretty complex circuit and well above my level of electronics skill to try and decipher, so I did not try.
And once again thank you to Jeremy for sending me the part.