BC547

The BC547 is a very popular NPN bipolar junction transistor (BJT) used for general-purpose low-power amplification and switching. You’ll see it everywhere—from student projects to commercial electronic circuits.

Key Features

• Type: NPN transistor

• Low cost & widely available

• Low noise performance – good for audio and signal circuits

• Small size (TO-92 package)

• Easy to use in basic electronic designs

Pin Configuration (Front view – flat side facing you)

1. Collector (C)

2. Base (B)

3. Emitter (E)

(Always double-check the datasheet, but this is the standard pinout.)

Electrical Specifications (Typical)

• Collector-Emitter Voltage (Vce): 45V

• Collector Current (Ic): 100mA (max)

• Power Dissipation: 500mW

• DC Current Gain (hFE): 110 – 800

• Transition Frequency: ~300 MHz

Applications

• Audio signal amplification

• Switching circuits

• LED driver circuits

• Sensor interfacing

• Relay driver (low current)

• DIY electronics & educational projects

• Signal processing stages

Advantages

• Reliable and stable performance

• Works well at low voltages

• Ideal for beginners and prototyping

• Compatible with breadboards