BD912 Technical Summary

Overview

The BD912 is a silicon epitaxial-base NPN power transistor designed for high-power applications requiring robust performance and reliability. Housed in a Jedec TO-220 plastic package, this component is optimized for use in power amplification, switching, and linear regulation circuits. Its construction ensures efficient thermal dissipation, making it suitable for demanding environments where heat management is critical.

With a high current and voltage rating, the BD912 is engineered to deliver stable operation under varying load conditions. Its epitaxial-base structure enhances switching speed and reduces saturation voltage, contributing to improved efficiency in power conversion applications.

Features

• High Current Capability: Supports collector currents up to 12A, making it ideal for power-intensive applications.
• High Voltage Rating: Collector-emitter voltage (V_CEO) of 100V ensures reliable operation in high-voltage circuits.
• Low Saturation Voltage: Minimizes power loss and improves efficiency in switching applications.
• Fast Switching Speed: Optimized for high-frequency operation, reducing transition losses.
• Thermal Stability: TO-220 package provides excellent heat dissipation, ensuring reliable performance under thermal stress.
• Complementary PNP Option: Available as part of a complementary pair (with BD911/BD913 for PNP configurations).
• Robust Construction: Designed to withstand high surge currents and transient voltages.

Applications

The BD912 is versatile and finds use in a wide range of power electronics applications, including:

• Power Supplies: Used in linear and switching regulators for efficient voltage conversion.
• Motor Control: Suitable for driving DC motors and solenoids in industrial and automotive systems.
• Audio Amplifiers: Provides high-current output stages in audio power amplifiers.
• Inverters and Converters: Key component in DC-AC and DC-DC power conversion circuits.
• Relay and Solenoid Drivers: Ensures reliable switching in electromechanical control systems.
• Lighting Systems: Used in high-power LED drivers and HID ballasts.

Electrical Characteristics

The following table summarizes the key electrical specifications of the BD912 under standard test conditions (T_A = 25°C unless otherwise noted):

Absolute Maximum Ratings

• Collector-Emitter Voltage (V_CEO): 100V
• Collector-Base Voltage (V_CBO): 120V
• Emitter-Base Voltage (V_EBO): 5V
• Collector Current (I_C): 12A (continuous), 15A (peak)
• Base Current (I_B): 6A
• Total Power Dissipation (P_tot): 40W (at T_C = 25°C)
• Junction Temperature (T_j): -55°C to +150°C
• Storage Temperature (T_stg): -55°C to +150°C

Thermal Characteristics

• Thermal Resistance, Junction-to-Case (R_th(j-c)): 1.67°C/W
• Thermal Resistance, Junction-to-Ambient (R_th(j-a)): 62.5°C/W (without heatsink)

On-State Characteristics

• Collector-Emitter Saturation Voltage (V_CE(sat)): 0.5V (typical) at I_C = 6A, I_B = 0.6A
• Base-Emitter Saturation Voltage (V_BE(sat)): 1.2V (typical) at I_C = 6A, I_B = 0.6A
• DC Current Gain (h_FE): 40 (min) to 320 (max) at I_C = 3A, V_CE = 4V

Switching Characteristics

• Turn-On Time (t_on): 0.3µs (typical) at I_C = 6A, V_CC = 50V
• Turn-Off Time (t_off): 1.0µs (typical) under the same conditions
• Fall Time (t_f): 0.5µs (typical)

Package Information

The BD912 is housed in a TO-220 plastic package, which is widely used for power transistors due to its excellent thermal and mechanical properties. Below are the key package details:

TO-220 Package Dimensions

• Package Type: TO-220AB (Jedec compliant)
• Lead Material: Copper alloy, tin-plated
• Mounting Style: Through-hole
• Weight: Approximately 2.0 grams
• Terminal Configuration: Collector, Base, Emitter (arranged in standard TO-220 pinout)

Mechanical Drawing

The TO-220 package has the following critical dimensions (typical values):

• Total Height: 16.0 mm (max)
• Lead Length: 14.0 mm (min)
• Lead Spacing: 2.54 mm (between leads)
• Mounting Hole Diameter: 3.5 mm (recommended)

Thermal Considerations

For optimal performance, proper heatsinking is recommended when operating the BD912 near its maximum power dissipation limits. The TO-220 package is designed to be mounted on a heatsink using thermal interface material to minimize junction-to-ambient thermal resistance.

Conclusion

The BD912 is a high-performance NPN power transistor that combines high current capability, fast switching, and excellent thermal properties. Its TO-220 package ensures ease of integration into a variety of power electronics designs, from motor drives to audio amplifiers. With robust electrical characteristics and reliable construction, the BD912 is a preferred choice for engineers designing high-power applications.