2sk3903.pdf datasheet:

2SK3903 TOSHIBA Field Effect Transistor Silicon N-Channel MOS Type (-MOSVI) 2SK3903 Switching Regulator Applications Unit: mm Low drain-source ON resistance: RDS (ON) = 0.32 (typ.) High forward transfer admittance: Yfs = 7.5 S (typ.) Low leakage current: IDSS = 100 A (max) (VDS = 600 V) Enhancement model: Vth = 2.0~4.0 V (VDS = 10 V, ID = 1 mA) Absolute Maximum Ratings (Ta = 25C) Characteristic Symbol Rating UnitDrain-source voltage VDSS 600 VDrain-gate voltage (RGS = 20 k) VDGR 600 VGate-source voltage VGSS 30 VDC (Note 1) ID 14 1. GATE Drain current A 2. DRAIN (HEATSINK) Pulse (Note 1) IDP 56 3. SOURCE Drain power dissipation (Tc = 25C) PD 150 WSingle pulse avalanche energy JEDEC EAS 806 mJ(Note 2)JEITA SC-65 Avalanche current IAR 14 ATOSHIBA 2-16C1B Repetitive avalanche energy (Note