The 2SK2639-01 is an N‑channel MOSFET from the FAP‑IIS series, rated for 450 V drain‑source voltage and up to 10 A continuous drain current. It offers high‑speed switching, low on‑resistance, and low driving power, making it suitable for switching regulators, UPS, DC‑DC converters, and power amplifiers.
The datasheet lists absolute maximum ratings such as 450 V VDS, 10 A continuous drain current, and 100 W power dissipation, as well as detailed electrical characteristics (threshold voltage, on‑state resistance, capacitances) and thermal parameters (thermal resistance to air and case). Typical output and capacitance curves are also provided.