This part is a kind of semiconductor called MDD5N40.

Function of this product has N-Channel MOSFET.

Manufacturers : MagnaChip

Image and pinout :

Some of the text within the PDF file :

MDI5N40 N-channel MOSFET 400V MDI5N40/MDD5N40 N-Channel MOSFET 400V, 3.4 A, 1.6Ω General Description The MDI5N40 / MDD5N40 use advanced Magnachip’s MOSFET Technology, which provides low on-state resistance, high switching performance and excellent quality. MDI5N40 is suitable device for SMPS, HID and general purpose applications. Features VDS = 400V ID = 3.4A RDS(ON) ≤ 1.6Ω Applications Power Supply PFC Ballast @VGS = 10V @VGS = 10V D I-PAK G D S (TO-251) G S Absolute Maximum Ratings (Ta = 25oC) Characteristics Drain-Source Voltage Gate-Source Voltage Continuous Drain Current Pulsed Drain Current(1) Power Dissipation Peak Diode Recovery dv/dt(3) Repetitive Pulse Avalanche Energy(4) Single Pulse Avalanche Energy(4) Junction and Storage Temperature Range TC=25oC TC=100oC TC [ ... ]

MDD5N40 PDF Datasheet Download