BD441 NPN Transistor Pinout Datasheet

Introduction

The BD441 is a high-power NPN silicon epitaxial transistor designed for use in audio amplifiers, power regulators, and switching circuits. With its robust current handling capability and excellent linearity, it is widely used in applications that demand reliability, low distortion, and moderate frequency response. The transistor offers a strong combination of voltage, current, and power ratings suitable for medium-power stages.

Engineered in a TO-126 plastic package, the BD441 provides efficient heat dissipation and can be easily mounted to small heatsinks for improved thermal management. Its design allows smooth operation in amplifier output stages, motor drivers, and control circuits. Because of its good gain stability and low saturation voltage, the transistor ensures efficient operation even under heavy load conditions.

BD441 NPN Transistor

The BD441 belongs to the BD43x/BD44x transistor family, which includes complementary pairs for balanced circuit design. This makes it ideal for use in push-pull configurations and complementary amplifiers, where both NPN and PNP devices are required for symmetrical signal operation.

Pinout of BD441

Key Features

• NPN silicon epitaxial type for reliable power switching
• Suitable for medium-power audio and amplifier circuits
• Designed for both linear and switching applications
• High DC current gain and low saturation voltage
• Good thermal and electrical stability
• Compatible for use with its PNP complementary device
• Compact TO-126 plastic case for efficient mounting

Specifications/Characteristics

• Collector-Emitter Voltage (VCEO): 80 V
• Collector-Base Voltage (VCBO): 80 V
• Emitter-Base Voltage (VEBO): 5 V
• Collector Continuous Current (IC): 4 A
• Peak Collector Current (ICM): 7 A
• Total Power Dissipation (Ptot): 36 W at Tc = 25 °C
• Junction Temperature (Tj max): 150 °C
• Storage Temperature Range (Tstg): –65 °C to +150 °C
• DC Current Gain (hFE): 40 (minimum)
• Transition Frequency (fT): 3 MHz

Pin Configuration

Comparison BD441 (NPN) vs BD442 (PNP Complementary)

• The BD441 is an NPN transistor, while the BD442 is its PNP complementary counterpart, both sharing identical voltage, current, and power characteristics but opposite polarity. BD441 conducts during the positive half of the signal cycle, making it suitable for low-side or positive-switching operations.
• In contrast, BD442 conducts during the negative half of the signal or high-side operation. When used together in a push-pull amplifier, they deliver symmetrical output performance with reduced distortion. Their electrical matching ensures efficient and balanced performance in both linear and switching applications.

More Circuit Layouts

Key Applications of BD441 NPN Transistor

• Audio power amplifiers and output drivers
• Power supply and voltage regulator circuits
• Switching and control stages
• DC motor control and relay drivers
• Complementary push-pull configurations

PNP Complimentary Transistor

• The PNP complementary device to BD441 is BD442

Equivalent Transistors of BD441 NPN Transistor

• BD437
• BD439
• 2N5191
• MJE5200
• TIP41 series (with similar ratings)

(Pin configuration of some transistors mentioned here may different from BD441).

Datasheet of BD441 NPN Transistor

Click the following Button to download the datasheet of BD441 Transistor :

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