This part is a kind of semiconductor called 5M02659RN.

Function of this product has Power Switch.

Manufacturers : Fairchild Semiconductor

Image and pinout :

Some of the text within the PDF file :

www.fairchildsemi.com KA5x02xx-SERIES KA5H0265RC, KA5M0265R, KA5L0265R, KA5H02659RN/KA5M02659RN, KA5H0280R, KA5M0280R Fairchild Power Switch(FPS) Features • Precision Fixed Operating Frequency (100/67/50kHz) • Low Start-up Current (Typ. 100uA) • Pulse by Pulse Current Limiting • Over Load Protection • Over Voltage Protection (Min. 25V) • Internal Thermal Shutdown Function • Under Voltage Lockout • Internal High Voltage Sense FET • Auto-Restart Mode Description The Fairchild Power Switch(FPS) product family is specially designed for an off-line SMPS with minimal external components. The Fairchild Power Switch(FPS) consist of high voltage power SenseFET and current mode PWM IC. Included PWM controller features integrated fixed oscillator, under voltage lock out, leadin [ ... ]

5M02659RN PDF Datasheet Download