BU508AW High-Voltage NPN Transistor

Overview

The BU508AW is a high-voltage, high-speed switching NPN transistor housed in a robust plastic envelope. Designed primarily for horizontal deflection applications in CRT-based displays, this component offers reliable performance in high-voltage environments. Its construction ensures efficient switching capabilities, making it suitable for demanding power applications.

This transistor is engineered to handle high collector-emitter voltages while maintaining fast switching speeds, which is critical for deflection circuits in televisions and monitors. The BU508AW is widely recognized for its durability and efficiency in high-stress applications.

Features

• High Voltage Capability: Supports collector-emitter voltages up to 1500V, making it ideal for deflection circuits.
• Fast Switching Speed: Optimized for high-speed switching applications, reducing power losses.
• High Current Handling: Capable of handling collector currents up to 8A, ensuring robust performance.
• Low Saturation Voltage: Minimizes power dissipation during operation.
• Plastic Envelope Package: Provides mechanical strength and thermal stability.
• Wide Operating Temperature Range: Suitable for use in varying environmental conditions.

Applications

The BU508AW is primarily used in applications requiring high-voltage switching and deflection. Key applications include:

• CRT Horizontal Deflection Circuits: Essential for driving the horizontal deflection coils in televisions and monitors.
• Switch-Mode Power Supplies (SMPS): Used in high-voltage power supply circuits due to its fast switching characteristics.
• Electronic Ballasts: Provides efficient switching in lighting applications.
• High-Voltage Inverters: Suitable for circuits requiring high-voltage inversion.
• Industrial Power Control: Used in industrial equipment requiring high-voltage handling.

Electrical Characteristics

The following table summarizes the key electrical characteristics of the BU508AW under standard test conditions (unless otherwise specified):

Absolute Maximum Ratings

• Collector-Emitter Voltage (V_CEO): 1500V
• Collector-Base Voltage (V_CBO): 1500V
• Emitter-Base Voltage (V_EBO): 7V
• Collector Current (I_C): 8A (continuous)
• Base Current (I_B): 4A (peak)
• Total Power Dissipation (P_tot): 100W (at 25°C)
• Operating 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_thJC): 1.25°C/W
• Thermal Resistance, Junction-to-Ambient (R_thJA): 62.5°C/W

Switching Characteristics

• Turn-On Time (t_on): 1.0µs (typical)
• Turn-Off Time (t_off): 6.0µs (typical)
• Fall Time (t_f): 1.5µs (typical)

Package Information

The BU508AW is packaged in a TO-3P plastic envelope, which provides excellent thermal and mechanical properties. The package is designed for easy mounting and efficient heat dissipation.

Package Dimensions

• Package Type: TO-3P (Plastic)
• Weight: Approximately 15g
• Mounting Style: Through-hole
• Pin Configuration:
  • Pin 1: Base
  • Pin 2: Collector
  • Pin 3: Emitter

Mechanical Drawing

The TO-3P package features a robust design with the following key dimensions (in millimeters):

• Overall Height: 20.5mm
• Body Diameter: 15.5mm
• Lead Spacing: 5.45mm (between Base and Emitter)
• Mounting Hole Diameter: 3.5mm

Reliability and Compliance

The BU508AW complies with industry standards for high-voltage transistors and is designed for long-term reliability. It undergoes rigorous testing to ensure performance under high-stress conditions.

• RoHS Compliance: Meets Restriction of Hazardous Substances directives.
• Flammability Rating: UL 94V-0 compliant for plastic materials.

Conclusion

The BU508AW is a high-performance NPN transistor optimized for high-voltage switching applications, particularly in CRT horizontal deflection circuits. Its combination of high voltage tolerance, fast switching speeds, and robust packaging makes it a reliable choice for demanding electronic designs. Whether used in consumer electronics or industrial power systems, the BU508AW delivers consistent performance and durability.