This part is a kind of semiconductor called MDF18N50.

Function of this product has N-Channel MOSFET.

Manufacturers : MagnaChip

Image and pinout :

Some of the text within the PDF file :

MDF18N50 N-channel MOSFET 500V MDF18N50 N-Channel MOSFET 500V, 18 A, 0.27Ω General Description The MDF18N50 uses advanced MagnaChip’s MOSFET Technology, which provides low on-state resistance, high switching performance and excellent quality. MDF18N50 is suitable device for SMPS, high speed switching and general purpose applications. Features VDS = 500V VDS = 550V ID = 18A RDS(ON) ≤ 0.27Ω @ Tjmax @VGS = 10V @VGS = 10V Applications Power Supply PFC High Current, High Speed Switching D G G D S S Absolute Maximum Ratings (Ta = 25oC) Characteristics Drain-Source Voltage Drain-Source Voltage @ Tjmax Gate-Source Voltage Continuous Drain Current (※) Pulsed Drain Current(1) Power Dissipation Peak Diode Recovery dv/dt(3) Single Pulse Avalanche Energy(4) Junction and Storage Tempe [ ... ]

MDF18N50 PDF Datasheet Download