View kst55 datasheet:

KST55/56 PNP EPITAXIAL SILICON TRANSISTOR DRIVER TRANSISTOR SOT-23 ABSOLUTE MAXIMUM RATINGS (T =25 ) A Characteristic Symbol Rating Unit Collector Base Voltage VCBO :KST55 -60 V :KST56 -80 V Collector-Emitter Voltage VCEO :KST55 -60 V :KST56 -80 V Emitter-Base Voltage VEBO -4 V Collector Current IC -500 mA Collector Dissipation PC 350 mW Storage Temperature TSTG 150 Thermal Resistance junction /w RTH(j-a) 357 to Ambient • Refer to KSP55 for graphs 1. Base 2. Emitter 3. Collector ELECTRICAL CHARACTERISTICS (T =25 ) A Characteristic Symbol Test Conditions Min Max Unit Collector-Emitter Breakdown Voltage BVCEO IC= -1mA, IB=0 :KST55 -60 V :KST56 -80 V V Collector-Base Breakdown Voltage BVEBO IE= -100 , IC=0 -4 Collector Cut-off Current ICBO VCE= -60V, IE=0