View stp21n05 datasheet:

STP21N05L STP21N05LFI N - CHANNEL ENHANCEMENT MODE LOW THRESHOLD POWER MOS TRANSISTOR TYPE V R I DSS DS(on) D STP21N05L 50 V < 0.085 ? 21 A STP21N05LFI 50 V < 0.085 ? 14 A TYPICAL RDS(on) = 0.065 ? AVALANCHE RUGGED TECHNOLOGY 100% AVALANCHE TESTED REPETITIVE AVALANCHE DATA AT 100oC 3 3 LOW GATE CHARGE 2 2 1 1 LOGIC LEVEL COMPATIBLE INPUT o 175 C OPERATING TEMPERATURE APPLICATION ORIENTED TO-220 ISOWATT220 CHARACTERIZATION APPLICATIONS HIGH CURRENT, HIGH SPEED SWITCHING SOLENOID AND RELAY DRIVERS REGULATORS INTERNAL SCHEMATIC DIAGRAM DC-DC & DC-AC CONVERTERS MOTOR CONTROL, AUDIO AMPLIFIERS AUTOMOTIVE ENVIRONMENT (INJECTION, ABS, AIR-BAG, LAMPDRIVERS, Etc.) ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit STP21N05L STP21N05LFI VDS Drain-sou