BCxxx General Purpose Transistors [TO-92]

BC Series NPN PNP Power Transistors TO-92 Package 3-Legs

The BC series transistors are a family of general-purpose bipolar junction transistors (BJTs) commonly used in low-power electronic circuits. These transistors are widely utilized in amplification and switching applications. Here's an overview of some common BC series transistors along with their technical specifications:

Common BC Series Transistors

1. BC107 / BC108 / BC109 (NPN)
2. BC177 / BC178 / BC179 (PNP)
3. BC547 / BC548 / BC549 (NPN)
4. BC557 / BC558 / BC559 (PNP)

Technical Specifications

1. BC107 / BC108 / BC109 (NPN Transistors)

• Maximum Collector-Emitter Voltage (Vceo): 45V (BC107), 20V (BC108), 25V (BC109)
• Maximum Collector Current (Ic): 100mA
• Power Dissipation (Ptot): 300mW
• DC Current Gain (hFE): 110-800 (depending on the specific type and current)
• Transition Frequency (fT): 150MHz (typical for BC107/108), 200MHz (typical for BC109)

2. BC177 / BC178 / BC179 (PNP Transistors)

• Maximum Collector-Emitter Voltage (Vceo): 45V (BC177), 20V (BC178), 25V (BC179)
• Maximum Collector Current (Ic): 100mA
• Power Dissipation (Ptot): 300mW
• DC Current Gain (hFE): 110-800 (depending on the specific type and current)
• Transition Frequency (fT): 150MHz (typical for BC177/178), 200MHz (typical for BC179)

3. BC547 / BC548 / BC549 (NPN Transistors)

• Maximum Collector-Emitter Voltage (Vceo): 45V (BC547), 30V (BC548), 30V (BC549)
• Maximum Collector Current (Ic): 100mA
• Power Dissipation (Ptot): 500mW
• DC Current Gain (hFE): 110-800 (depending on the specific type and current)
• Transition Frequency (fT): 150MHz (typical for BC547/548), 200MHz (typical for BC549)

4. BC557 / BC558 / BC559 (PNP Transistors)

• Maximum Collector-Emitter Voltage (Vceo): 45V (BC557), 30V (BC558), 30V (BC559)
• Maximum Collector Current (Ic): 100mA
• Power Dissipation (Ptot): 500mW
• DC Current Gain (hFE): 110-800 (depending on the specific type and current)
• Transition Frequency (fT): 150MHz (typical for BC557/558), 200MHz (typical for BC559)

Applications

• Amplifiers: These transistors are commonly used in low-signal amplification stages.
• Switches: Suitable for switching small currents in electronic circuits.
• Oscillators and Signal Generators: Due to their high-frequency response, they are used in high-frequency applications.
• Audio Preamplifiers: Their low noise characteristics make them ideal for audio preamplifier circuits.

Package Types

BC series transistors typically come in TO-92 packages, which are convenient for breadboard prototyping and general-purpose use in various electronic projects.

Conclusion

BC series transistors are versatile components essential for many electronic circuit designs. Their different specifications cater to various needs, making them a popular choice among hobbyists and professionals alike.