BC635 NPN Transistor Pinout Datasheet

Introduction

The BC635 is a general-purpose NPN bipolar junction transistor (BJT) commonly used in low to medium-power amplification and switching applications. It belongs to the BC63x family of transistors, designed for audio frequency and driver stages. The BC635 offers a moderate collector current handling capacity and high voltage tolerance, making it suitable for amplifiers, signal processing, and low-frequency switching circuits.

Built using silicon epitaxial planar technology, the BC635 provides excellent linearity, gain stability, and low noise characteristics. Its TO-92 package ensures easy integration into compact circuits and is favored in both analog and digital projects. Due to its high DC gain and low saturation voltage, it is often used in driver stages of audio amplifiers, control boards, and relay drivers.

BC635 NPN Transistor

The BC635 is also recognized for its reliable performance, thermal stability, and versatility across consumer, industrial, and educational electronics. It serves as an efficient choice for developers looking for a balance between performance and cost in signal amplification and small power-switching designs.

BC635 Pinout

Pin Configuration

Key Features

• NPN silicon epitaxial planar transistor
• Designed for audio frequency and low-power applications
• Excellent linear amplification characteristics
• Low collector-emitter saturation voltage
• High current gain (hFE) and stable performance
• Reliable operation and thermal stability
• Compact TO-92 package for easy PCB mounting

Characteristics

• Collector-Base Voltage (VCBO): 60V
• Collector-Emitter Voltage (VCEO): 45V
• 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
• Operating and Storage Junction Temperature: –55°C to +150°C
• Package Type: TO-92

Comparison Summary: BC635 vs BC637 vs BC639

The BC635 has the lowest voltage and current ratings in this family, making it ideal for low-power signal amplification.
The BC637 offers slightly higher voltage (VCEO = 60V) and current handling capability, providing more flexibility in driver circuits.
The BC639 is the most robust of the trio, with higher voltage (VCEO = 80V) and power dissipation, suited for high-voltage and high-gain applications.

In short:

• BC635 → Low-power amplifier use
• BC637 → Medium-power amplifier or driver use
• BC639 → High-voltage and performance-demanding circuits

More Circuit Layouts

Key Applications of BC635 Transistor

• Audio amplifier driver stages
• Low to medium-power signal amplifiers
• Switching and control circuits
• Relay and LED drivers
• Hobby and educational electronic projects
• General-purpose transistor in analog designs

PNP Complementary Transistor

• The PNP complementary transistor of BC635 is BC636. Both are matched pairs often used in push-pull amplifier stages or complementary switching configurations.

Equivalent of BC635 NPN Transistor

• BC637
• BC639
• 2N2222
• 2N3904
• S8050
• MPS2222A

Always verify the pin configuration and ratings before substitution.

Datasheet of BC635 NPN Transistor

Click the following Button to download the datasheet of BC635 Transistor :

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