This part is a kind of semiconductor called CXA3812M.

Function of this product has AC-DC Controller.

Manufacturers : Sony

Image and pinout :

Some of the text within the PDF file :

AC-DC Controller CXA3812M Description The CXA3812M is the current resonant controller IC and has optimum configuration to realize various power supply circuits easily and compactly. (Applications: Power supply circuit, etc.) Features  Overcurrent timer latch  Soft start function  Minimum frequency adjustment  Pulse overcurrent load detection  Adjacent 2-pin short protection  Various protection functions including overvoltage and overcurrent Structure BiCMOS silicon monolithic IC Package 14-pin SOP Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the opera [ ... ]

CXA3812M PDF Datasheet Download