BC109C 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): 420 to 800
• Transition Frequency, min: 150 MHz
• Noise Figure, max: 1.5 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 BC109C transistor can have a current gain of 420 to 800. The gain of the BC109 will be in the range from 200 to 800, for the BC109B it will be in the range from 200 to 450.The MMBT5089 (SOT-23) and MMBTH10 (SOT-23) is the SMD version of the BC109C transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the BC109C with the BC108 or BC108C.