BD682 Pinout, Equivalent, Applications, Datasheet

The BD682 is a high-gain PNP Darlington power transistor in a TO-126 package, ideal for amplification, regulation, and power switching. This article details BD682 pinout, datasheet, and practical uses.

Introduction to BD680 PNP Transistor

The BD682 is a PNP Darlington power transistor designed for medium-power amplification and control applications. It features high DC current gain, excellent linear response, and a TO-126 package optimized for heat dissipation.

This transistor can handle collector currents up to 4A and voltages up to 80V, making it suitable for audio power stages, voltage regulators, and motor drivers. Its Darlington configuration internally connects two PNP transistors, offering very high gain with low base current, a key benefit in control and amplification circuits.

BD682 is the complementary PNP pair of the BD681 NPN transistor, often used together in push-pull output stages for symmetrical signal amplification and efficient audio output.

BD682 PNP Transistor

Pinout of BD682

Understanding the BD682 Pinout Configuration

The BD682 pinout follows the standard TO-126 configuration, making it simple to integrate into existing designs or replace other TO-126 PNP transistors. Understanding the pin functions ensures proper circuit connectivity and reliable operation.

Pin Configuration of BD682 Pinout

Key Features of BD682 Transistor

• High-gain PNP Darlington configuration
• Collector current up to 4A for medium-load operations
• Collector-Emitter voltage of 80V
• Compact TO-126 package for easy mounting
• Excellent thermal stability and linear amplification
• Complementary to BD681 (NPN Darlington)
• Suitable for amplifier and switching circuits
• Ideal for low base drive control applications

BD682 Transistor Datasheet and Specifications

• Collector-Emitter Voltage (Vceo): 80 V
• Collector-Base Voltage (Vcbo): 80 V
• Emitter-Base Voltage (Vebo): 5 V
• Collector Current (Ic): 4 A
• Power Dissipation (Ptot): 40 W
• DC Current Gain (hFE): Minimum 750
• Transition Frequency (fT): 3 MHz typical
• Junction Temperature (Tj max): 150 °C
• Polarity: PNP
• Package Type: TO-126

According to the BD682 transistor datasheet, this PNP Darlington is suited for medium-power control and amplification. Its low input drive requirement and high current capacity make it ideal for audio, automation, and relay control circuits.

Working Principle of BD682 Transistor

The BD682 operates using a Darlington pair configuration, in which two PNP transistors are internally connected to multiply the overall current gain. When a negative voltage is applied to the base relative to the emitter, the transistor conducts, allowing current to flow from emitter to collector.

This setup enables large output currents with minimal base current, significantly improving circuit efficiency. The BD682 is thus excellent for low-input, high-output applications like audio drivers, signal amplifiers, and control switches.

More Circuit Layouts

Typical Applications of BD682

• Audio power amplifiers and pre-drivers
• Voltage regulators and control circuits
• Relay and solenoid drivers
• Motor control systems and speed regulators
• Push-pull output stages with BD681 (NPN)
• LED and lamp controllers
• Industrial automation and switching circuits

NPN Complementary Transistor

The NPN complementary transistor of BD682 is BD681. When used together, they form a complementary Darlington pair ideal for push-pull amplifier configurations.

In such designs, BD681 handles the positive signal cycle, while BD682 handles the negative, producing balanced amplification and minimal distortion. This complementary performance makes them ideal for audio systems, servo control modules, and motor driver circuits.

Equivalent Transistors and Alternatives

If BD682 is unavailable, the following transistors can be used as equivalents or substitutes after checking voltage, gain, and package compatibility:

• BD680 (PNP Darlington, lower power version)
• TIP127 (PNP Darlington transistor in TO-220 package)
• MJE802 (PNP Darlington transistor)
• 2N6043 (PNP Darlington transistor)

Each provides similar gain and current handling characteristics suitable for amplification, control, and switching circuits.

Comparison BD682 vs BD681 Complementary Transistors

The BD682 (PNP) and BD681 (NPN) are designed as complementary Darlington power transistors for symmetrical signal amplification.

While BD682 conducts during the negative half of a signal cycle, BD681 operates during the positive half, creating a push-pull configuration that enhances linearity and efficiency in amplifier circuits.

Both share identical ratings, 80 V voltage limit, 4 A current capacity, and TO-126 packaging — ensuring seamless integration in balanced amplifier and motor control applications.

Frequently Asked Questions (FAQ)

What is the BD682 transistor used for?

BD682 is commonly used in audio amplifiers, regulators, and control circuits requiring high gain and current capacity.

What type of transistor is BD682?

It is a PNP Darlington transistor, meaning it consists of two PNP transistors connected internally for high current amplification.

What is the BD682 pin configuration?

Facing the flat side, the pins from left to right are Emitter (1), Collector (2), Base (3).

What is the complementary transistor for BD682?

The complementary transistor is BD681, an NPN Darlington transistor with matching ratings.

Can I use TIP127 instead of BD682?

Yes, TIP127 can replace BD682 if your circuit allows a TO-220 package and similar power ratings.

Conclusion

The BD682 PNP Darlington transistor is a highly efficient and reliable component for medium-power switching, regulation, and amplification circuits. It provides high current gain with minimal input drive, making it excellent for control and power management systems.

When paired with BD681, it delivers superior push-pull amplifier performance, ensuring low distortion, stable operation, and improved signal fidelity. The compact TO-126 package allows easy integration in space-restricted circuit boards while maintaining strong thermal characteristics.

Datasheet & Pinout of BD682 NPN Transistor

Click the following Button to download the datasheet of BD682 Transistor :

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