This part is a kind of semiconductor called 2SC1645S.

Function of this product has High-gain Amplifier Transistor (-32V/ -0.3A).

Manufacturers : Rohm

Image and pinout :

Some of the text within the PDF file :

2SD1383K / 2SC1645S Transistors High-gain Amplifier Transistor (32V , 0.3A) 2SD1383K / 2SC1645S zFeatures 1) Darlington connection for high DC current gain. 2) Built-in 4kΩ resistor between base and emitter. 3) Complements the 2SD852K / 2SA830S. zExternal dimensions (Unit : mm) 2SD1383K 2.9 0.4 (3) 1.1 0.8 zCircuit diagram (2) (1) 0.95 0.95 0.15 1.9 (1)Emitter B (2)Base (3)Collector Each lead has same dimensions RBE 4kΩ 2SC1645S E : Emitter B : Base C : Collector E 3.0 4.0 2.0 (15Min.) zPackaging specifications Type Package hFE Marking Code Basic ordering unit (pieces) 2SD1383K SMT3 B W∗ T146 3000 2SC1645S SPT B − TP 5000 3Min. 0.45 2.5 5.0 (1) (2) (3) 0.5 0.45 (1)Emitter (2)Collector (3)Base Taping specifications ∗ Denotes hFE zAbsolute [ ... ]

2SC1645S PDF Datasheet Download