BC548 Bipolar Transistor

• Type - NPN
• Collector-Emitter Voltage: 30 V
• Collector-Base Voltage: 30 V
• Emitter-Base Voltage: 5 V
• Collector Current: 0.1 A
• Collector Dissipation - 0.5 W
• DC Current Gain (h_fe) - 110 to 800
• Transition Frequency - 150 MHz
• Noise Figure - 2 dB
• Operating and Storage Junction Temperature Range -65 to +150 °C
• Package - TO-92

The BC548 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 collector, base, and emitter leads.
Here is an image showing the pin diagram of this transistor.The BC548 transistor might have a current gain anywhere between 110 and 800. The gain of the BC548A will be in the range from 110 to 220, BC548B ranges from 200 to 450, BC548C ranges from 420 to 800.The complementary PNP transistor to the BC548 is the BC558.The SMD versions of the BC548 are available as the BC848 (SOT-23), BC848W (SOT-323), BC849 (SOT-23) and BC849W (SOT-323).You can replace the BC548 with the BC547, BC549 or BC550