This part is a kind of semiconductor called L6565D.
Function of this product has QUASI-RESONANT SMPS CONTROLLER.
Manufacturers : STMicroelectronics
Image and pinout :

Some of the text within the PDF file :
L6565 QUASI-RESONANT SMPS CONTROLLER QUASI-RESONANT (QR) ZERO-VOLTAGESWITCHING (ZVS) TOPOLOGY s LINE FEED FORWARD TO DELIVER CONSTANT POWER vs. MAINS CHANGE s FREQUENCY FOLDBACK FOR OPTIMUM STANDBY EFFICIENCY s PULSE-BY-PULSE & HICCUP-MODE OCP s ULTRA-LOW START-UP (< 70µA) AND QUIESCENT CURRENT (< 3.5mA) s DISABLE FUNCTION (ON/OFF CONTROL) s 1% PRECISION (@ T j = 25°C) INTERNAL REFERENCE VOLTAGE s ±400mA TOTEM POLE GATE DRIVER WITH UVLO PULL-DOWN s BLUE ANGEL, ENERGY STAR, ENERGY 2000 COMPLIANT APPLICATIONS s TV/MONITOR SMPS s AC-DC ADAPTERS/CHARGERS s DIGITAL CONSUMER s PRINTERS, FAX MACHINES, PHOTOCOPIERS AND SCANNERS s DIP8(Minidip) SO-8 ORDERING NUMBERS: L6565N L6565D DESCRIPTION The L6565 is a current-mode primary controller IC, specifically designed to buil [ ... ]
L6565D PDF Datasheet Download
