This part is a kind of semiconductor called 2SD2170.

Function of this product has Medium Power Transistor(Motor/ Relay drive) (90 / 2A).

Manufacturers : Rohm

Image and pinout :

Some of the text within the PDF file :

2SD2170 Transistors Medium Power Transistor 20 (Motor, Relay drive) (90 + −10 , 2A) 2SD2170 !Features 1) Built-in zener diode between collector and base. 2) Zener diode has low dispersion. 3) Strong protection against reverse power surges due to "L" loads. 4) Darlington connection for high DC current gain. 5) Built-in resistor between base and emitter. 6) Built-in damper diode. !External dimensions (Units : mm) 4.0 1.0 2.5 0.5 1.5 0.4 (1) 3.0 0.5 (3) 4.5 1.6 (2) (1) Base(Gate) (2) Collector(Drain) (3) Emitter(Source) 1.5 0.4 ROHM : MPT3 EIAJ : SC-62 !Absolute maximum ratings (Ta=25°C) Parameter Collector-base voltage Collector-emitter voltage Emitter-base voltage Collector current Collector power dissipation Junction temperature Storage temperature Symbol VCBO VCES VEBO IC [ ... ]

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