High power npn transistors st tip31a power transistor npn polarity 60v collector emitter breakdown voltage 60v collector base breakdown voltage 3a collector current 2w power 20 dc current gain 3mhz transition frequency to 220 case 198g weight suitable for a wide variety of switching and amplifier applications series and shunt regulators driver and output stages of hi fi amplifiers tip31a 60v npn gp transistor