View tk7a500 datasheet:

TK7A50D TOSHIBA Field Effect Transistor Silicon N Channel MOS Type (π-MOSⅦ) TK7A50D Switching Regulator Applications Unit: mm • Low drain-source ON-resistance: RDS (ON) = 1.0 Ω (typ.) • High forward transfer admittance: ⎪Yfs⎪ = 2.5 S (typ.) • Low leakage current: IDSS = 10 μA (max) (VDS = 500 V) • Enhancement mode: Vth = 2.4 to 4.4 V (VDS = 10 V, ID = 1 mA) Absolute Maximum Ratings (Ta = 25°C) Characteristics Symbol Rating Unit Drain-source voltage VDSS 500 V Gate-source voltage VGSS ±30 V DC (Note 1) ID 7 Drain current A Pulse (t = 1 ms) IDP 28 (Note 1) 1: Gate Drain power dissipation (Tc = 25°C) 2: Drain PD 35 W 3: Source Single pulse avalanche energy EAS 129 mJ (Note 2) JEDEC ⎯ Avalanche current IAR 7 A JEITA SC-67 R