Popular transistors.

BC549 transistor.
Pinout. Datasheet.

Type Designator: BC549.
Package: TO-92, 1-collector, 2-base, 3-emitter.
Material of transistor: Si
Polarity: NPN
Total Devise power dissipation |PD|: 0.5W
Collector-base breakdown voltage |VCBO|: 30V
Collector-emitter breakdown voltage |VCEO|: 30V
Emitter-base breakdown voltage |VEBO|: 5V
Maximum collector current |Ic max|: 0.1A
Maximum junction temperature |Tj|: +150 C
Transition frequency (ft) : 100-250 MHz
Collector Output Capacitance |Ccbo|:2,5pF
Collector-emitter saturation voltage|VCE|:0,25V(IC=10mA,IB=0,5mA),
0,6V(IC=100mA,IB=5mA)
Base-emitter saturation voltage|VBE|:0,7V(IC=10mA,IB=0,5mA),
0,9V(IC=100mA,IB=5mA)
Forward current transfer ratio |hFE| : 420-800,(IC=2mA,VCE=5V), 125-260(BC549A), 240-500(BC549B), 450-800 (BC549C)
Noise Figure, (NF): 4dB