BD179 NPN Transistor Pinout Datasheet

Introduction

The BD179 is a silicon NPN power transistor designed for medium power switching and audio amplifier applications. It delivers a high collector current and wide voltage handling capability, making it ideal for audio output stages, driver circuits, voltage regulators, and signal amplification. With a robust structure and consistent electrical performance, it is widely used in hi-fi audio amplifiers, DC motor control, and general-purpose power electronics.

Encapsulated in a TO-126 package, the BD179 offers excellent heat dissipation and mechanical durability. It supports a collector-emitter voltage (VCEO) of up to 80 V and a collector current of 2 A, enabling stable operation under demanding load conditions. This transistor ensures low distortion and stable gain characteristics, which are crucial for delivering clear and linear signal amplification in audio and switching circuits.

BD179 NPN Transistor

Because of its strong electrical performance and thermal reliability, the BD179 is widely used in class AB push-pull amplifier stages, often paired with its PNP complementary transistor BD180 or BD178. Its high-frequency response, typically around 3 MHz, allows it to perform well in medium-speed switching and signal driver applications across consumer and industrial electronics.

Pinout of BD179

Key Features

• NPN silicon transistor for medium-power amplification and switching
• Low saturation voltage for improved efficiency
• High transition frequency for clean audio response
• Robust TO-126 package for better heat dissipation
• Excellent linearity and gain stability

Specifications/Characteristics

• Collector-Emitter Voltage (VCEO): 80 V
• Collector-Base Voltage (VCBO): 80 V
• Emitter-Base Voltage (VEBO): 5 V
• Collector Current (IC): 3 A
• Total Power Dissipation (Ptot): 15 W with adequate heat-sink
• DC Current Gain (hFE): 40 – 250 depending on operating current
• Transition Frequency (fT): 3 MHz typical
• Operating Junction Temperature (Tj): up to 150 °C
• Package Type: TO-126 (plastic, fully-isolated tab)

Pin Configuration

Comparison Summary (BD175, BD177, BD179)

• The BD175 is an early-generation NPN transistor rated for 60 V and 2 A applications, suitable for moderate power and low-frequency amplifier circuits.
• The BD177, also an NPN transistor, improves thermal stability and offers better linear response, making it ideal for balanced audio power amplifiers and switching systems.
• The BD179 stands as the most advanced among them, with a higher voltage tolerance of 80 V and superior gain at higher frequencies, making it perfect for high-fidelity amplifier stages, driver circuits, and demanding power applications where both stability and performance are required.

More Circuit Layouts

Key Applications of BD179 NPN Transistor

• Audio power amplifiers and output driver stages
• Class-AB push-pull amplifier circuits
• Voltage regulator and control circuits
• Motor driver and relay control systems
• Switching and signal amplification in consumer electronics
• Power supply feedback and protection stages

PNP Complimentary Transistor

• The PNP complementary transistor of the BD179 is BD180 (in some cases BD178 is used as well).
  Both transistors are paired in push-pull output configurations and class AB amplifier stages, ensuring symmetric current handling and clean signal reproduction.

Equivalent Transistors of BD179 NPN Transistor

• BD135
• BD139
• BD177
• MJE3055
• TIP31
• 2N6121
• 2SD882

(Pin configuration of some transistors mentioned here may different from BD179).

Datasheet of BD179 NPN Transistor

Click the following Button below to download the datasheet of BD179 Transistor :

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