View bu406 sam datasheet:

BU406/406H/408 NPN EPITAXIAL SILICON TRANSISTOR HIGH VOLTAGE SWITCHING TO-220 USE IN HORIZONTAL DEFLECTION OUTPUT STAGE ABSOLUTE MAXIMUM RATINGS Characteristic Symbol Rating Unit Collector-Base Voltage VCBO 400 V Collector-Emitter Voltage VCEO 200 V Emitter-Base Voltage VEBO 6 V Collector Current IC 7 A 1.Base 2.Collector 3.Emitter Collector Peck Current ICM 10 A Base Current IB 4 A Collector Dissipation ( TC=25 ) PC 60 W Junction Temperature TJ 150 Storage Temperature TSTG -55 ~150 ELECTRICAL CHARACTERISTICS (Tc =25 ) Characteristic Symbol Test Conditions Min Max Unit Collector Cutoff Current (VBE=0) ICES VCE = 400V, VBE = 0 5 mA VCE = 250V, VBE = 0 100 uA VCE = 250V, VBE = 0, TC = 150 1 mA Emitter Cutoff Current (IC=0) IEBO VBE = 6V, IC = 0 1 mA Coll