The 2SD1664-Q from Galaxy Century Microelectronics is a Bipolar Junction Transistor with Emitter Base Voltage 5 V, Emitter Cut off Current 0.5 µA, Collector Base Voltage 40 V, Collector Cut off Current 0.5 µA, Collector Emitter Breakdown Voltage 32 V. Tags: Surface Mount, NPN Transistor. More details for 2SD1664-Q can be seen below.