BD678 PNP Power Darlington Transistor 60V 4A TO-126 Package

BD678 PNP Power Darlington Transistor 60V 4A TO-126 Package

The BD678 is a high-current PNP Darlington transistor designed for medium-to-high power amplification and switching applications. With a collector-emitter voltage of 60V and a collector current of up to 4A, it delivers high current gain, low saturation voltage, and excellent thermal stability.

Encased in a TO-126 package, the BD678 ensures efficient heat dissipation, making it ideal for audio amplifiers, motor drivers, voltage regulators, and medium-power switching circuits. Its Darlington configuration provides enhanced current amplification, making it suitable for driving moderate-to-heavy loads in industrial, educational, and hobbyist electronics projects.

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Features:

• Transistor Type: PNP Silicon Darlington
• Package: TO-126 (medium-power, thermally efficient)
• Collector-Emitter Voltage (V_CE): 60V
• Collector Current (I_C): 4A
• Power Dissipation (P_tot): Up to 80W (with proper heatsink)
• High Current Gain (hFE): 1000–5000 (typical for Darlington pair)
• Low Saturation Voltage: Efficient switching and amplification
• High Thermal Stability: Reliable operation under high current loads
• Durable & Reliable: Long-term professional and hobbyist use
• Complementary Device: Works with BD677 (NPN) in push-pull amplifier stages

Applications:

• Audio Amplifiers: High-gain driver and output stages
• Relay & Motor Drivers: Efficiently drives motors, relays, and solenoids
• Voltage Regulators: Provides stable voltage and current
• Switching Circuits: Medium-to-high power load switching
• Push-Pull Amplifier Designs: Complementary with BD677 (NPN)
• Industrial, Educational & Hobby Projects: Ideal for experimentation and prototyping
• Darlington Amplification Circuits: High current gain for medium-to-high power applications

bd678-transistor-datasheet