BC171A Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 45 V
• Collector-Base Voltage, max: 50 V
• Emitter-Base Voltage, max: 6 V
• Collector Current − Continuous, max: 0.1 A
• Collector Dissipation: 0.3 W
• DC Current Gain (h_fe): 110 to 220
• Noise Figure, max: 10 dB
• Operating and Storage Junction Temperature Range: -65 to +150 °C
• Package: TO-92

The BC171A 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 BC171A transistor can have a current gain of 110 to 220. The gain of the BC171 will be in the range from 110 to 450, for the BC171B it will be in the range from 200 to 450.The 2SC1623 (SOT-23), BC847 (SOT-23), BC847A (SOT-23), BC847AW (SOT-323), BC847W (SOT-323), BC850 (SOT-23), BC850A (SOT-23), BC850AW (SOT-323), BC850W (SOT-323) and KSC1623 (SOT-23) is the SMD version of the BC171A transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the BC171A with the 2N5822, BC337, BC337-16, BC445, BC447, BC485, BC485A, BC487, BC487A, BC489, BC489A, BC546, BC546A, BC547, BC547A, BC550 or BC550A.