View 2sk1365 datasheet:

2SK1365 TOSHIBA Field Effect Transistor Silicon N Channel MOS Type (?-MOSII.5) 2SK1365 Switching Power Supply Applications Unit: mm Low drain-source ON resistance : RDS (ON) = 1.5 ? (typ.) High forward transfer admittance : |Y | = 4.0 S (typ.) fs Low leakage current : I = 300 µA (max) (V = 800 V) DSS DS Enhancement-mode : Vth = 1.5~3.5 V (V = 10 V, I = 1 mA) DS D Maximum Ratings (Ta = 25°C) Characteristics Symbol Rating Unit Drain-source voltage VDSS 1000 V Drain-gate voltage (RGS = 20 k?) VDGR 1000 V Gate-source voltage VGSS ±20 V DC (Note 1) ID 7 Drain current A Pulse (Note 1) IDP 21 Drain power dissipation (Tc = 25°C) PD 90 W Channel temperature Tch 150 °C Storage temperature range Tstg -55~150 °C JEDEC ? JEITA ? Thermal Characteristics