BC639 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 80 V
• Collector-Base Voltage, max: 80 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 0.5 A
• Collector Dissipation: 0.625 W
• DC Current Gain (h_fe): 40 to 160
• Transition Frequency, min: 200 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-92

The BC639 is manufactured in a plastic TO-92 case. When looking at the flat side with the leads pointed downward, the three leads emerging from the transistor are, from left to right, the emitter, collector, and base leads.
Here is an image showing the pin diagram of this transistor.The complementary PNP transistor to the BC639 is the BC640.You can replace the BC639 with the KSC1009C.