View 2sk2604 datasheet:

2SK2604 TOSHIBA Field Effect Transistor Silicon N Channel MOS Type (?-MOSIII) 2SK2604 Switching Regulator Applications Unit: mm Low drain-source ON resistance : RDS = 1.9 ? (typ.) (ON) High forward transfer admittance : |Y | = 3.8 S (typ.) fs Low leakage current : I = 100 µA (max) (V = 640 V) DSS DS Enhancement-mode : Vth = 2.0~4.0 V (V = 10 V, I = 1 mA) DS D Maximum Ratings (Ta = 25°C) Characteristics Symbol Rating Unit Drain-source voltage VDSS 800 V Drain-gate voltage (RGS = 20k ?) VDGR 800 V Gate-source voltage VGSS ±30 V DC (Note 1) ID 5 A Drain current Pulse (Note 1) IDP 15 A 1. GATE Drain power dissipation (Tc = 25°C) PD 125 W 2. DRAIN (HEAT SINK) Single pulse avalanche energy EAS 370 mJ 3. SOURCE (Note 2) Avalanche current IAR