BC178A 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 260
• 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 BC178A transistor can have a current gain of 125 to 260. The gain of the BC178 will be in the range from 125 to 500, for the BC178B it will be in the range from 240 to 500.The complementary NPN transistor to the BC178A is the BC108A.The BC858 (SOT-23), BC858W (SOT-323), BC859 (SOT-23) and BC859W (SOT-323) is the SMD version of the BC178A transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the BC178A with the 2N2907, 2N3251, BC177, BC177A, BC297, BC297-7, BC298, BC298-7, BC478, BCY70, BCY71 or BCY72.