BC639 NPN Transistor Pinout Datasheet

Introduction

The BC639 is a high-voltage NPN bipolar junction transistor (BJT) designed for audio frequency amplification, signal processing, and medium-power switching applications. It is part of the BC63x transistor series, which includes BC635 and BC637, known for their stable performance and reliability in linear amplification circuits. With a collector-emitter voltage (VCEO) of up to 80V and a maximum collector current (IC) of 1A, the BC639 is ideal for applications requiring higher voltage handling capability and efficient signal amplification.

Manufactured using silicon epitaxial planar technology, the BC639 provides excellent frequency response, high DC current gain, and low saturation voltage, making it suitable for audio amplifier drivers, voltage regulators, and switching circuits. The transistor is enclosed in the TO-92 package, offering easy handling and compatibility with compact PCB layouts. It can efficiently drive small motors, lamps, and relays due to its solid current handling ability.

BC639 NPN Transistor

The BC639 transistor is widely used in audio amplifier output stages, signal boosters, and low-frequency driver circuits, where stable performance and thermal reliability are essential. Its high gain and robust design make it a preferred choice for both DIY electronics projects and professional analog circuit designs. Additionally, it is often used as a replacement for older medium-power NPN transistors in consumer and industrial applications.

BC639 Pinout

Pin Configuration

Key Features

• High-voltage NPN transistor suitable for medium-power circuits
• Excellent linear amplification performance
• Low saturation voltage for efficient operation
• High DC gain and frequency response
• Stable and reliable under varying thermal conditions
• Compatible with standard TO-92 package layouts

Characteristics

• Collector-Base Voltage (VCBO): 100V
• Collector-Emitter Voltage (VCEO): 80V
• Emitter-Base Voltage (VEBO): 5V
• Collector Current (IC): 1A maximum
• Power Dissipation (Ptot): 1.25W
• DC Current Gain (hFE): 40 to 160
• Transition Frequency (fT): 100MHz typical
• Junction Temperature Range: –55°C to +150°C
• Package Type: TO-92

Comparison Summary: BC635 vs BC637 vs BC639

• The BC635 is the lowest-rated device in the BC63x family, designed for low-voltage and low-power applications with a collector-emitter voltage of around 45V.
• The BC637 offers a moderate improvement with 60V VCEO and 1A collector current, making it suitable for medium-power signal and driver circuits.
• The BC639 is the highest-rated transistor in this series, providing 80V collector-emitter voltage and robust thermal stability, ideal for high-voltage amplifier and switching applications.

In simple terms:

• BC635 → Low-voltage general-purpose transistor
• BC637 → Mid-level performance for moderate power circuits
• BC639 → High-voltage, high-performance transistor for demanding applications

More Circuit Layouts

Key Applications of BC639 Transistor

• Audio amplifier driver and output stages
• Medium-power switching circuits
• Voltage and current amplification circuits
• Relay, solenoid, and small motor drivers
• Signal preamplifiers and audio frequency amplifiers
• General-purpose and educational electronic projects

PNP Complementary Transistor

• The PNP complementary transistor of BC639 is BC640. Both are commonly used together in push-pull amplifier circuits and audio power amplifier stages, offering balanced NPN/PNP pairing for improved signal symmetry and distortion control.

Equivalent of BC639 NPN Transistor

• BC635
• BC637
• 2N2219
• 2N2222
• BD135
• MPS2222A
• 2N3904
• S8050

Always verify the pin configuration and ratings before substitution.

Datasheet of BC639 NPN Transistor

Click the following Button to download the datasheet of BC639 Transistor :

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