This part is a kind of semiconductor called K3728-01MR.

Function of this product has 2SK3728-01MR.

Manufacturers : Fuji Semiconductors

Image and pinout :

Some of the text within the PDF file :

( DataSheet : ) 2SK3728-01MR FUJI POWER MOSFET N-CHANNEL SILICON POWER MOSFET Outline Drawings [mm] TO-220F 200305 Super FAP-G Series Features High speed switching Low on-resistance No secondary breadown Low driving power Avalanche-proof Applications Switching regulators UPS (Uninterruptible Power Supply) DC-DC converters Maximum ratings and characteristicAbsolute maximum ratings (Tc=25°C unless otherwise specified) Item Drain-source voltage Continuous drain current Pulsed drain current Gate-source voltage Repetitive or non-repetitive Maximum Avalanche Energy Maximum Drain-Source dV/dt Peak Diode Recovery dV/dt Max. power dissipation Operating and storage temperature range Isolation Voltage Symbol Ratings V DS 900 VDSX *5 900 ID ±2.2 ID(puls] ±8.8 VGS ±30 IAR *2 [ ... ]

K3728-01MR PDF Datasheet Download