BF259 Pinout, Equivalent, Application, Datasheet

The BF259 is an NPN high-voltage video amplifier transistor built for wideband and fast signal amplification. This article explains the BF259 pinout, electrical ratings, working principle, applications, and alternatives for high-voltage video and RF amplifier designs.

Introduction

The BF259 is a high-voltage NPN bipolar junction transistor designed specifically for video amplification and wideband signal processing. With an exceptionally high voltage rating and stable frequency response, it is widely used in CRT video output stages, oscilloscopes, and other high-voltage analog circuits.

Pin Configuration / Pinout of BF259 Transistor

Understanding the BF259 Pinout Configuration

The BF259 comes in a robust TO-39 metal package, offering excellent heat dissipation and electrical shielding. The three terminals are:

Correct identification of the BF259 pinout is critical for safe and reliable operation in high-voltage circuits.

Note: DATASHEET DOWNLOAD button is provided end of this article.

BF259 Key Features

• NPN high-voltage video amplifier transistor
• Designed for wideband and fast signal amplification
• Very high collector-emitter voltage capability
• Excellent thermal stability with TO-39 metal can
• Suitable for video, pulse, and RF amplifier circuits
• Proven reliability in demanding applications

BF259 Specifications/Characteristics

• Collector-Emitter Voltage (Vceo): 300V
• Collector-Base Voltage (Vcbo): 300V
• Emitter-Base Voltage (Vebo): 5V
• Collector Current (Ic): 100mA
• Total Power Dissipation (Ptot): 5W
• Junction Temperature (Tj): 200°C
• Storage Temperature (Tstg): −65°C to 200°C
• DC Current Gain (hFE): 25
• Transition Frequency (fT): 90MHz

Key Applications of BF259 Transistor

• High-voltage video amplifier stages
• CRT display and monitor circuits
• Oscilloscope vertical amplifier sections
• Wideband signal and pulse amplifiers
• High-voltage RF amplification circuits

BF259 Equivalent / Alternatives

(Verify pin compatibility before using substitutions)

Equivalent Transistors: BF257, BF258
Alternative Devices: 2N3583, MJE340 (with appropriate biasing)

More Circuit Layouts

Working Principle of BF259

The BF259 operates by allowing a small base current to control a much larger collector current. When the base-emitter junction is forward biased, charge carriers flow efficiently through the transistor, enabling stable amplification of wideband video signals at very high operating voltages.

Frequently Asked Questions (FAQ)

Q1: Why is BF259 used in video amplifier circuits?
Its high voltage rating and wide bandwidth make it ideal for video signal amplification.

Q2: What package does BF259 use?
BF259 is packaged in a TO-39 metal can.

Q3: Can BF259 operate at very high voltages?
Yes, it supports up to 300V collector-emitter voltage.

Q4: Is BF259 suitable for RF applications?
Yes, it can be used in medium-frequency RF and pulse amplifier circuits.

Conclusion

The BF259 NPN high-voltage video amplifier transistor is a powerful and reliable solution for wideband, high-voltage amplification. Its robust TO-39 package, strong thermal performance, and proven electrical characteristics make it well suited for professional video and high-speed analog circuit designs.

Datasheet of BF259 Transistor

Click the following Button below to download the datasheet of BF259 :

More projects, You may like:

• Video Transmitter DIY Homemade FM Radio Transmitter
• Adjustable Power Supply DIY Battery Charger
• 12V-220V 500 Watt inverter DIY Homemade
• MPPT Solar Charge Controller DIY Homemade
• DIY LA4440 bass amplifier homemade

For more project and circuit diagrams, you can go through the Schematics in the main menu where you can find many interesting projects and circuit diagrams like audio amplifier circuits, voltage booster circuit, battery charger circuit and timer circuits etc., which are all beginner circuit projects. Feel free to check them out!

Thank you for visiting the article.