2sk3561.pdf datasheet:

2SK3561 TOSHIBA Field Effect Transistor Silicon N Channel MOS Type (-MOSVI) 2SK3561 Switching Regulator Applications Unit: mm Low drain-source ON resistance: RDS (ON) = 0.75 (typ.) High forward transfer admittance: |Yfs| = 6.5S (typ.) Low leakage current: IDSS = 100 A (VDS = 500 V) Enhancement mode: Vth = 2.0~4.0 V (VDS = 10 V, ID = 1 mA) Maximum Ratings (Ta = 25C) Characteristics Symbol Rating UnitDrain-source voltage VDSS 500 VDrain-gate voltage (RGS = 20 k) VDGR 500 VGate-source voltage VGSS 30 VDC (Note 1) ID 8 Drain current A Pulse (t = 1 ms) IDP 32 (Note 1)1: Gate 2: Drain Drain power dissipation (Tc = 25C) PD 40 W3: Source Single pulse avalanche energy EAS 312 mJ (Note 2)Avalanche current IAR 8 AJEDEC Repetitive avalanche energy (Note 3) EAR 4 mJJEITA SC-67Channel temperature Tch 15