This part is a kind of semiconductor called 1250B65.

Function of this product has Current-Mode PWM Controller.

Manufacturers : ON Semiconductor

Image and pinout :

Some of the text within the PDF file :

NCP1250 Current-Mode PWM Controller for Off-line Power Supplies The NCP1250 is a highly integrated PWM controller capable of delivering a rugged and high performance offline power supply in a tiny TSOP−6 or PDIP−8 package. With a supply range up to 28 V, the controller hosts a jittered 65 kHz or 100 kHz switching circuitry operated in peak current mode control. When the power on the secondary side starts to decrease, the controller automatically folds back its switching frequency down to a minimum level of 26 kHz. As the power further goes down, the part enters skip cycle while limiting the peak current. Over Power Protection (OPP) is a difficult exercise especially when no−load standby requirements drive the converter specifications. The ON proprietary integrated OPP lets you harne [ ... ]

1250B65 PDF Datasheet Download