BU508AF – High-Voltage NPN Power Transistor by STMicroelectronics
The Bipolar Transistors - BJT BU508AF by STMicroelectronics are robust, high-voltage NPN transistors designed for switching and amplification in high-power applications. Known for their ruggedness and efficiency, these devices are widely used in horizontal deflection stages of CRTs, power inverters, and motor drivers. The BU508AF features enhanced thermal performance in a fully isolated TO-3PF package, making it ideal for thermally demanding environments.
In this blog, we’ll dive into the key specifications, features, applications, mounting tips, and how to purchase or download the datasheet from Xon Electronics.
Technical Specifications of BU508AF
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Manufacturer: STMicroelectronics
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Part Number: BU508AF
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Type: Bipolar Junction Transistor (BJT)
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Transistor Type: NPN
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Collector-Emitter Voltage (Vce): 700V
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Collector Current (Ic): 8A
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Power Dissipation: 75W
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Package Type: TO-3PF (Fully Isolated)
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Transition Frequency: 3 MHz
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Operating Temperature Range: -65°C to +150°C
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Category: Transistors, Bipolar Transistors - BJT by STMicroelectronics
Built for performance and durability, the BU508AF Bipolar Transistors - BJT by STMicroelectronics are ideal for designers seeking high-voltage, high-current solutions in compact formats.
Key Features of BU508AF
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High Voltage Tolerance (700V) – Ideal for power switching in CRTs and industrial drives
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Large Collector Current (8A) – Supports high-power applications
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Low Saturation Voltage – Improves efficiency and reduces heat generation
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Fully Isolated Package (TO-3PF) – Simplifies thermal management and mounting
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Reliable Avalanche Ruggedness – Withstands high-energy switching surges
These advantages make Bipolar Transistors - BJT by STMicroelectronics a trusted choice in power electronics, from legacy display systems to modern automation hardware.
Applications of BU508AF Power Transistor
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CRT Horizontal Deflection Circuits
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Inverter and Converter Circuits
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Electric Motor Controllers
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Welding Equipment
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High-Voltage Switching Supplies
Whether you’re restoring vintage systems or building industrial power controllers, the BU508AF Bipolar Transistors - BJT by STMicroelectronics offer the robustness and reliability you need.
Mounting & Thermal Tips
To install the BU508AF:
[Step 1] Align the TO-3PF package to a heatsink with appropriate thermal compound
[Step 2] Screw or clip down securely for maximum surface contact
[Step 3] Ensure electrical insulation is maintained (thanks to the fully isolated tab)
[Step 4] Solder leads to PCB pads or connect with high-current terminals
[Step 5] Test for proper switching and collector-emitter voltage drop
Thanks to its TO-3PF packaging, the Bipolar Transistors - BJT by STMicroelectronics simplify mechanical design while optimizing thermal performance.
Use Case Scenario – CRT Monitor Repair
Scenario: A repair technician working on legacy CRT monitors needed a high-voltage, rugged NPN transistor for horizontal deflection.
Problem: Original parts were discontinued and modern replacements lacked isolation.
Solution: The BU508AF’s 700V, 8A rating and isolated package made it a drop-in replacement.
Result: Successful restoration, reduced heat issues, and improved service life.
This shows how Bipolar Transistors - BJT by STMicroelectronics remain essential in both legacy and modern applications.
Download Datasheet for BU508AF
Need full specs, thermal profiles, or safe operating curves?
[Download BU508AF Datasheet from Xon Electronics]
Why Buy from Xon Electronics?
Xon Electronics stocks a full range of Bipolar Transistors - BJT by STMicroelectronics, including the BU508AF:
- 100% Original STMicroelectronics Products
- Global Shipping – USA, India, Australia, Europe & more
- Fast Dispatch & OEM Bulk Availability
- Application Support and Technical Assistance
- Secure Online Ordering Platform
Buy today from www.xonelec.com and power your project with trusted STMicroelectronics transistors.
Conclusion
The BU508AF Bipolar Transistors - BJT by STMicroelectronics provide powerful switching performance, high-voltage capability, and reliable operation in industrial and consumer power systems. With a TO-3PF isolated package and excellent ruggedness, Bipolar Transistors - BJT by STMicroelectronics are a preferred solution for demanding electronic designs—now available globally from Xon Electronics.
FAQs – BU508AF STMicroelectronics Transistor
Q1. What is the max collector-emitter voltage?
700V.
Q2. What is the current handling capacity?
Up to 8A continuous collector current.
Q3. What kind of package does it use?
Fully isolated TO-3PF.
Q4. Can it be used in motor control circuits?
Yes, suitable for inverters and high-voltage drivers.
Q5. Where can I buy it globally?
At www.xonelec.com with shipping to USA, India, Australia, Europe, and more.