This part is a kind of semiconductor called S9018.

Function of this product has NPN General Purpose Transistors.

Manufacturers : Weitron

Image and pinout :

Some of the text within the PDF file :

S9018 3 1 2 SOT-23 V CEO Value 18 25 4.0 50 200 1.14 875 S9018=J8 100u 100 100 18 25 4.0 E=15 Vdc, I E= 0 ) 20 3.0 O 0.1 0.1 0.1 u u u WEITRON http://www.weitron.com.tw S9018 ELECTRICAL CHARACTERISTICS (TA=25 C unless otherwise noted) (Countinued) Characteristics Symbol Min Max Unit ON CHARACTERISTICS DC Current Gain (IC=1.0 mAdc, VCE=5.0 Vdc) Collector-Emitter Saturation Voltage (IC=10 mAdc, IB=1.0mAdc) Base-Emitter Saturation Voltage (IC=10 mAdc, IB=1.0mAdc) hFE (1) VCE(sat) VBE(sat) 70 190 0.5 1.4 Vdc Vdc SMALL-SIGNAL CHARACTERISTICS Current-Gain-Bandwidth Product (IC=5.0 mAdc, VCE=5.0 Vdc, f=400MHz) fT 600 MHz WEITRON http://www.weitron.com.tw S9018 VCE = 5V I C , CO LLECTOR CURRENT(mA) I B=90uA I B=60uA I B=50uA I B=40uA I B=30uA I B=20uA I B=10uA hFE, DC CURRENT [ ... ]

S9018 PDF Datasheet Download