This part is a kind of semiconductor called 2SK1944-01.

Function of this product has N-channel MOS-FET.

Manufacturers : Fuji Electric

Image and pinout :

Some of the text within the PDF file :

2SK1944-01 FAP-IIA Series > Features High Speed Switching Low On-Resistance No Secondary Breakdown Low Driving Power High Voltage VGS = ± 30V Guarantee Avalanche Proof N-channel MOS-FET 900V 2,8Ω 5A 100W > Outline Drawing > Applications Switching Regulators UPS DC-DC converters General Purpose Power Amplifier > Maximum Ratings and Characteristics - Absolute Maximum Ratings (TC=25°C), unless otherwise specified Item Drain-Source-Voltage Drain-Gate-Voltage (RGS=20KΩ) Continous Drain Current Pulsed Drain Current Gate-Source-Voltage Max. Power Dissipation Operating and Storage Temperature Range Symbol V DS V DGR ID I D(puls) V GS PD T ch T stg Rating 900 900 5 20 ±30 100 150 -55 ~ +150 Unit V V A A V W °C °C > Equivalent Circuit - Electrical Characteristics (TC=25°C), unless [ ... ]

2SK1944-01 PDF Datasheet Download