This part is a kind of semiconductor called STR-A6069H.
Function of this product has Off-Line PWM Controllers.
Manufacturers : Sanken Electric
Image and pinout :
Some of the text within the PDF file :
Off-Line PWM Controllers with Integrated Power MOSFET STR-A6000 Series General Descriptions The STR-A6000 series are power ICs for switching power supplies, incorporating a MOSFET and a current mode PWM controller IC. The low standby power is accomplished by the automatic switching between the PWM operation in normal operation and the burst-oscillation under light load conditions. The product achieves high cost-performance power supply systems with few external components. Features Current Mode Type PWM Control Brown-In and Brown-Out function Auto Standby Function No Load Power Consumption < 25mW Operation Mode Normal Operation - PWM Mode Standby Burst Oscillation Mode Random Switching Function Slope Compens [ ... ]