2sc6144.pdf datasheet:

isc Silicon NPN Power Transistors 2SC6144DESCRIPTIONCollector-Emitter Saturation Voltage-: V = 0.36V(Max.)@I = 6ACE(sat) CCollector-Emitter Breakdown Voltage-: V = 50V(Min)(BR) CEOMinimum Lot-to-Lot variations for robust deviceperformance and reliable operationAPPLICATIONSRelay drivers,lamp drivers,motor driversABSOLUTE MAXIMUM RATINGS(T =25)aSYMBOL PARAMETER VALUE UNITV Collector-Base Voltage 60 VCBOV Collector-Emitter Voltage 50 VCEOV Emitter-Base Voltage 5 VEBOI Collector Current-Continuous 10 ACI Collector Current-Pulse 13 ACMI Base Current 2 ABCollector Power DissipationP 25 WCT =25CT Max.Junction Temperature 150 jT Storage Ttemperature Range -55~150 stgTHERMAL CHARACTERISTICSSYMBOL PARAMETER MAX UNITThermal Resistance,Junction toR 5 /Wth j-cCase1isc Websitewww.iscsemi.