View stp5nk40z datasheet:

STP5NK40Z - STP5NK40ZFP STD5NK40Z - STD5NK40Z-1 N-CHANNEL 400V - 1.47? - 3A TO-220/TO-220FP/DPAK/IPAK Zener-Protected SuperMESH™Power MOSFET TYPE VDSS RDS(on) ID Pw STP5NK40Z 400 V < 1.8 ? 3 A 45 W STP5NK40ZFP 400 V < 1.8 ? 3 A 20 W STD5NK40Z 400 V < 1.8 ? 3 A 45 W STD5NK40Z-1 400 V < 1.8 ? 3 A 45 W 3 TYPICAL RDS(on) = 1.47 ? 2 1 EXTREMELY HIGH dv/dt CAPABILITY TO-220 TO-220FP 100% AVALANCHE TESTED GATE CHARGE MINIMIZED VERY LOW INTRINSIC CAPACITANCES 3 VERY GOOD MANUFACTURING 3 2 1 REPEATIBILITY 1 IPAK DPAK DESCRIPTION The SuperMESH™ series is obtained through an extreme optimization of ST’s well established strip- INTERNAL SCHEMATIC DIAGRAM based PowerMESH™ layout. In addition to pushing on-resistance significantly down, special care is tak- en to en