BC558A Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -30 V
• Collector-Base Voltage, max: -30 V
• Emitter-Base Voltage, max: -5 V
• Collector Current − Continuous, max: -0.1 A
• Collector Dissipation: 0.5 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 +150 °C
• Package: TO-92

The BC558A 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 BC558A transistor can have a current gain of 110 to 220. The gain of the BC558 will be in the range from 110 to 800, for the BC558B it will be in the range from 200 to 450, for the BC558C it will be in the range from 420 to 800.The complementary NPN transistor to the BC558A is the BC548A.The BC858 (SOT-23), BC858A (SOT-23), BC858AW (SOT-323), BC858W (SOT-323), BC859 (SOT-23), BC859A (SOT-23), BC859AW (SOT-323) and BC859W (SOT-323) is the SMD version of the BC558A transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the BC558A with the 2N5375, 2N5823, BC327, BC327-16, BC446, BC486, BC486A, BC488, BC488A, BC557, BC557A, BC559, BC559A, BC560 or BC560A.