BC178 Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -25 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): 125 to 500
• Transition Frequency, min: 200 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 BC178 transistor can have a current gain of 125 to 500. The gain of the BC178A will be in the range from 125 to 260, for the BC178B it will be in the range from 240 to 500.The complementary NPN transistor to the BC178 is the BC108.The BC858 (SOT-23), BC858W (SOT-323), BC859 (SOT-23) and BC859W (SOT-323) is the SMD version of the BC178 transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the BC178 with the BC177, BCY70, BCY71 or BCY72.