This part is a kind of semiconductor called AP3988I-HF.

Function of this product has N-CHANNEL ENHANCEMENT MODE POWER MOSFET.

Manufacturers : Advanced Power Electronics

Image and pinout :

Some of the text within the PDF file :

AP3988I-HF Halogen-Free Product Advanced Power Electronics Corp. ▼ 100% Avalanche Test ▼ Fast Switching Characteristic ▼ Simple Drive Requirement ▼ RoHS Compliant & Halogen-Free G S N-CHANNEL ENHANCEMENT MODE POWER MOSFET D BVDSS RDS(ON) ID 600V 0.75Ω 9A Description AP3988 series are specially designed as main switching devices for universal 90~265VAC off-line AC/DC converter applications. TO-220CFM type provide high blocking voltage to overcome voltage surge and sag in the toughest power system with the best combination of fast switching, ruggedized design and cost-effectiveness. G D S TO-220CFM(I) Absolute Maximum Ratings Symbol VDS VGS ID@TC=25℃ ID@TC=100℃ IDM PD@TC=25℃ EAS TSTG TJ Parameter Drain-Source Voltage Gate-Source Voltage Continuous Drain Current, V GS [ ... ]

AP3988I-HF PDF Datasheet Download