This part is a kind of semiconductor called K2401.
Function of this product has 2SK2401.
Manufacturers : Toshiba Semiconductor
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2SK2401 TOSHIBA Field Effect Transistor Silicon N Channel MOS Type (π−MOSV) 2SK2401 Chopper Regulator, DC−DC Converter and Motor Drive Applications z Low drain−source ON resistance : RDS (ON) = 0.13 Ω (typ.) z High forward transfer admittance : |Yfs| = 17 S (typ.) z Low leakage current : IDSS = 100 μA (max) (VDS = 200 V) z Enhancement mode : Vth = 1.5~3.5 V (VDS = 10 V, ID = 1 mA) Unit: mm Absolute Maximum Ratings (Ta = 25°C) Characteristics Symbol Rating Unit Drain−source voltage Drain−gate voltage (RGS = 20 kΩ) Gate−source voltage Drain current DC (Note 1) Pulse (Note 1) Drain power dissipation (Tc = 25°C) Single pulse avalanche energy (Note 2) Avalanche current Repetitive avalanche energy (Note 3) Channel temperature Storage temperature range V [ ... ]