View 2sa2018 datasheet:

2SA2018 Transistors Low-frequency Transistor 2SA2018 The transistor of 500mA class which went only into 2125 size conventionally was attained in 1608 sizes. Applications External dimensions (Units : mm) For switching, for muting. 1.6±0.2 1.0±0.1 0.7±0.1 0.5 0.5 +0.1 +0.1 0.2-0.05 Features 0.2-0.05 0.55±0.1 (1) (2) 1) A collector current is large. 0~0.1 2) Collector saturation voltage is low. (3) +0.1 VCE(sat) 250mV 0.3 -0.05 0.15±0.05 At IC = 200mA / IB = 10mA ROHM : EMT3 (1) EMITTER (2) BASE (3) COLLECTOR Absolute maximum ratings (Ta=25°C) Parameter Symbol Limits Unit Collector-base voltage VCBO 15 V Collector-emitter voltage VCEO 12 V IC 500 mA Collector current ICP 1 A * PC 150 mW Collector power dissipation Junction temperature Tj 150 ?C Stor