View tip121 datasheet:

TIP120/121/122 Medium Power Linear Switching Applications � Complementary to TIP125/126/127 TO-220 1 1.Base 2.Collector 3.Emitter NPN Epitaxial Darlington Transistor Equivalent Circuit Absolute Maximum Ratings TC=25�C unless otherwise noted C Symbol Parameter Value Units VCBO Collector-Base Voltage : TIP120 60 V : TIP121 80 V B : TIP122 100 V VCEO Collector-Emitter Voltage : TIP120 60 V : TIP121 80 V : TIP122 100 V R1 R2 VEBO Emitter-Base Voltage 5 V IC Collector Current (DC) 5 A E R1 ? 8k? R2 ? 0.12k? ICP Collector Current (Pulse) 8 A IB Base Current (DC) 120 mA PC Collector Dissipation (Ta=25�C) 2 W PC Collector Dissipation (TC=25�C) 65 W TJ Junction Temperature 150 �C TSTG Storage Temperature - 65 ~ 150 �C Electrical Characteristics TC=25�C unless other