BC547 NPN General Purpose Transistor – TO-92 Package for Switching & Amplification

The Essential NPN Transistor for Makers and Students

The Volt11 BC547 is a fundamental building block for any electronics toolkit.
As an NPN transistor, it acts as a high-speed electronic switch or a signal amplifier, allowing
low-power microcontrollers like Arduino to control devices that require more current.

Housed in the standard TO-92 package, the BC547 is easy to plug into breadboards
and solder onto PCBs. It is known for its high gain and low noise, making it equally effective for
amplifying weak sensor signals or acting as a logic gate component.

[Image of BC547 transistor pinout diagram]

Key Features:

• NPN Configuration: The standard choice for “low-side” switching in DC circuits.
• Breadboard Friendly: TO-92 plastic package with flexible leads for easy prototyping.
• High Gain: DC current gain (hFE) up to 800 for sensitive signal triggering.
• Direct NPN/PNP Pairing: Perfectly complements the BC558 PNP transistor for push-pull circuit designs.

Technical Specifications:

• Transistor Type: NPN
• Package Type: TO-92
• Collector-Emitter Voltage (Vce): 45V
• Collector-Base Voltage (Vcb): 50V
• Emitter-Base Voltage (Veb): 6V
• Continuous Collector Current (Ic): 100mA
• Power Dissipation (Pc): 500mW
• Transition Frequency (ft): 300MHz

Common Applications:

• Switching small loads (LEDs, Relays, Small DC Motors).
• Signal amplification in audio and radio circuits.
• Building logic gates (NOT, AND, OR) for educational projects.
• Sensor pre-amplification for analog-to-digital conversion.

Maker Tip: To use the BC547 as a switch, connect your load to the Collector and Ground to the Emitter. Sending a “High” signal (3.3V or 5V) through a base resistor (usually 1kΩ) to the Base pin will turn the transistor “ON.”