The BCP54T from Nexperia is a Bipolar Junction Transistor with Emitter Base Voltage 5 V, Emitter Cut off Current 100 nA, Collector Base Voltage 45 V, Collector Cut off Current 0.1 to 10 uA, Collector Emitter Breakdown Voltage 45 V. Tags: Surface Mount, NPN Transistor. More details for BCP54T can be seen below.