This part is a kind of semiconductor called STR-F6656.

Function of this product has Off-Line Quasi-Resonant Flayback Switching Regulators.

Manufacturers : Allegro Microsystems

Image and pinout :

Some of the text within the PDF file :

Series STR-F6600 INTERIM DATA SHEET (Subject to change without notice) February 22, 2000 OFF-LINE QUASI-RESONANT FLYBACK SWITCHING REGULATORS The Series STR-F6600 is specifically designed to satisfy the requirements for increased integration and reliability in off-line quasi-resonant flyback converters. The series incorporates a primary control and drive circuit with discrete avalanche-rated power MOSFETs. Data Sheet 28102.8 FDBK OSC. LATCH OCP UVLO OVP TSD Covering the power range from below 25 watts up to 300 watts for 100/115/230 VAC inputs, and up to 150 watts for 85 to 265 VAC universal input, these devices can be used in a range of applications, from battery chargers and set top boxes, to televisions, monitors, and industrial power supply units. Cycle-by-cycle current limitin [ ... ]

STR-F6656 PDF Datasheet Download