The AC817-40Q-7 from Diodes Incorporated is a Bipolar Junction Transistor with Emitter Base Voltage 5 V, Emitter Cut off Current 100 nA, Collector Base Voltage 50 V, Collector Cut off Current 100 nA, Collector Emitter Breakdown Voltage 45 V. Tags: Surface Mount, NPN Transistor. More details for AC817-40Q-7 can be seen below.