This part is a kind of semiconductor called 5S1265.

Function of this product has KA5S1265.

Manufacturers : Fairchild Semiconductor

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Some of the text within the PDF file :

www.fairchildsemi.com KA5S-SERIES KA5S0765C/KA5S09654QT/KA5S0965/ KA5S12656/KA5S1265 Fairchild Power Switch(FPS) Features • • • • • • • • • • • • • Wide Operating Frequency Range Up to 150Khz Lowest Cost SMPS Solution Lowest External Components Low Start-up Current (max:170uA) Low Operating Current (max:12mA) Internal High Voltage SenseFET Over Voltage Protection With Latch Mode (Min23V) Over Load Protection With Latch Mode Over Current Protection With Latch Mode Internal Thermal Protection With Latch Mode Pulse By Pulse Over Current Limiting Under Voltage Lockout With Hysteresis External Sync. Terminal TO-3P-5L 1 TO-220F-5L TO-220-5L 1 1 1. Drain 2. Gnd 3. VCC 4. FeedBack 5. Sync. Internal Block Diagram VCC 3 VCC UVLO + 15/9V Soft [ ... ]

5S1265 PDF Datasheet Download