BC108A Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 20 V
• Collector-Base Voltage, max: 30 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 0.1 A
• Collector Dissipation: 0.3 W
• DC Current Gain (h_fe): 110 to 220
• Transition Frequency, min: 150 MHz
• Noise Figure, max: 2 dB
• Operating and Storage Junction Temperature Range: -65 to +175 °C
• Package: TO-18

Here is an image showing the pin diagram of this transistor.The BC108A transistor can have a current gain of 110 to 220. The gain of the BC108 will be in the range from 110 to 800, for the BC108B it will be in the range from 200 to 450, for the BC108C it will be in the range from 420 to 800.The complementary PNP transistor to the BC108A is the BC178A.The MMBTH10 (SOT-23) is the SMD version of the BC108A transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the BC108A with the 2N2221A, 2N2222, 2N2222A, 2N3947, 2SC400, BC378 or NTE123A.