2sc4274.pdf datasheet:

INCHANGE Semiconductorisc Silicon NPN Power Transistor 2SC4274DESCRIPTIONHigh Collector-Emitter Sustaining Voltage-: V = 400V(Min)CEO(SUS)High Switching SpeedLow Collector Saturation Voltage100% avalanche testedMinimum Lot-to-Lot variations for robust deviceperformance and reliable operationAPPLICATIONSSwitching regulatorsDC-DC converterSolid state relayGeneral purpose power amplifiersABSOLUTE MAXIMUM RATINGS(T =25)aSYMBOL PARAMETER VALUE UNITV Collector-Base Voltage 500 VCBOV Collector-Emitter Voltage 400 VCEOV Emitter-Base voltage 10 VEBOI Collector Current-Continuous 10 ACI Base Current-Continuous 3 ABCollector Power DissipationP 40 WC@ T =25CT Junction Temperature 150 JT Storage Temperature Range -55~150 stgTHERMAL CHARACTERISTICSSYMBOL PARAMETER MAX UNITR Thermal Resistan