Description

BC547 NPN Transistor – 45V, 100 mA, TO‑92
The BC547 is a versatile NPN bipolar junction transistor (BJT) housed in a compact TO-92 package. Designed for low-power amplification and switching, this transistor is popular for general-purpose audio, signal and control applications. With a collector-emitter breakdown voltage of 45 V and continuous collector current up to 100 mA, the BC547 provides plenty of headroom for interfacing logic circuits, driving small loads and building analog amplifiers. Its high DC current gain (hFE) classification ranges from 110 to 800 across A/B/C variants, and the device exhibits very low saturation voltage and low noise for clean signal amplification. Thanks to a typical transition frequency around 300 MHz and operation up to +150 °C, the BC547 is suitable for both hobbyist projects and professional designs.

Features
• Voltage & current capability: collector–emitter voltage (VCEO) 45 V, collector–base voltage 50 V, emitter–base voltage 6 V; collector current up to 100 mA and power dissipation 500 mW.
• High gain classifications: hFE ranges from 110–220 (A class) through 200–450 (B) to 420–800 (C).
• Low saturation voltage: VCE(sat) ≈ 90 mV at 10 mA base current; < 0.2 V at 100 mA collector current.
• Fast switching: transition frequency (~300 MHz) supports high-frequency operation.
• Low noise: noise figure ≈ 2 dB for use in audio pre-amplifiers.
• Wide operating temperature: –65 °C to +150 °C.
• Package: TO-92 with 3 terminals – 1: Collector, 2: Base, 3: Emitter.

Applications
• Signal amplification: pre-amplifiers, oscillators and linear amplifier stages.
• Switching: LED drivers, relay drivers and TTL interface circuits.
• Audio circuits: low-noise stages in audio pre-amps.
• General purpose: analog/digital interfacing, sensor signal conditioning, hobbyist and educational projects.

Package contents
• 1 × BC547 NPN transistor.