This part is a kind of semiconductor called DL0165R.

Function of this product has FSDL0165R.

Manufacturers : Fairchild Semiconductor

Image and pinout :

Some of the text within the PDF file :

www.fairchildsemi.com FSDL0165RN Features Green Mode Fairchild Power Switch (FPSTM) • Internal Avalanche Rugged Sense FET • Consumes only 0.65W at 240VAC & 0.3W load with Advanced Burst-Mode Operation • Frequency Modulation for low EMI • Precision Fixed Operating Frequency • Internal Start-up Circuit • Pulse by Pulse Current Limiting • Abnormal Over Current Protection • Over Voltage Protection • Over Load Protection • Internal Thermal Shutdown Function • Auto-Restart Mode • Under Voltage Lockout • Low Operating Current (3mA) • Adjustable Peak Current Limit • Built-in Soft Start OUTPUT POWER TABLE 230VAC ±15%(3) PRODUCT FSDL321 FSDH321 FSDL0165RN FSDM0265RN FSDH0265RN FSDL0365RN FSDM0365RN FSDL0165RL FSDM0265RL FSDH0265RL FSDL0365RL FS [ ... ]

DL0165R PDF Datasheet Download