2N5550 Pinout, Equivalent, Application, Datasheet

The 2N5550 pinout follows the Emitter–Base–Collector (E–B–C) sequence in the TO-92 package, making it easy to identify and integrate into various circuits. The 2N5550 NPN transistor is a high-voltage, low-current silicon device designed for signal amplification, voltage regulation, and switching applications. With a collector-emitter voltage of 140 V and collector-base voltage of 160 V, it provides excellent electrical strength for use in audio preamplifiers, drivers, and general-purpose low-power electronics.

Introduction to 2N5550 NPN Transistor

The 2N5550 transistor is a silicon NPN bipolar junction transistor (BJT) specifically engineered for high-voltage and low-noise amplification. It is highly popular among hobbyists and professionals because of its reliable operation, compact TO-92 case, and wide availability. Its moderate current handling of 600 mA and power dissipation up to 625 mW make it suitable for audio amplifier input stages, signal switching, and voltage driver applications where clarity and low distortion are critical.

Thanks to its robust design, the 2N5550 NPN transistor performs effectively in environments where signal integrity and voltage stability are essential, making it a dependable choice for analog, digital, and control systems.

2N5550 NPN Transistor

Pinout of 2N5550

Understanding the 2N5550 Pinout Configuration

The 2N5550 pinout is arranged as Emitter–Base–Collector (E–B–C) when viewed from the flat side with leads pointing downward. This standard TO-92 pin arrangement simplifies prototyping and PCB mounting, ensuring compatibility with a wide range of transistor sockets and circuit layouts.

Pin Configuration of 2N5550 Pinout

Key Features of 2N5550 Transistor

• High-voltage NPN transistor for signal and switching circuits
• Low-noise operation ideal for audio and sensor systems
• Compact TO-92 package for breadboard and PCB use
• Excellent thermal and voltage stability
• Reliable gain control across a wide frequency range
• Suitable for both linear and switching applications

2N5550 Transistor Datasheet and Specifications

• Transistor Type: NPN Silicon BJT
• Collector–Emitter Voltage (Vce): 140 V
• Collector–Base Voltage (Vcb): 160 V
• Emitter–Base Voltage (Veb): 5 V
• Collector Current (Ic): 600 mA
• Power Dissipation (Ptot): 625 mW
• DC Current Gain (hFE): 40 – 250 (typical range)
• Transition Frequency (fT): 100 MHz (typical)
• Package Type: TO-92 Plastic
• Pin Sequence: Emitter–Base–Collector (E–B–C)

Working Principle of 2N5550 NPN Transistor

The 2N5550 NPN transistor works as a current amplifier and switch. A small base current regulates a much larger collector current. When a positive voltage is applied to the base relative to the emitter, the transistor becomes active, allowing current to flow between the collector and emitter.

Because of its high collector-emitter breakdown voltage (140 V), the 2N5550 can operate safely in high-voltage low-current environments. This makes it perfect for driver circuits, signal amplifiers, pulse circuits, and audio stages where both efficiency and accuracy are needed.

More Circuit Layouts

Typical Applications of 2N5550

• Audio preamplifier and driver circuits
• Signal switching and pulse shaping
• Voltage regulation and biasing networks
• Oscillator and timing circuits
• Sensor signal conditioning
• High-voltage logic level conversion
• General-purpose low-power applications

Equivalent Transistors and Alternatives

The 2N5550 transistor has several equivalents and substitutes that can be used if the original component is unavailable. Always check pin configuration and ratings before substitution.

Possible equivalents include:

• MPSA42 – High-voltage NPN with similar performance
• 2N5551 – Close electrical equivalent with higher gain range
• BC546B – General-purpose high-voltage NPN transistor
• 2SC945 – Suitable alternative for signal-level switching

Always verify pinout and package type before substitution.

Frequently Asked Questions (FAQ)

What is the 2N5550 transistor used for?

It is used for amplifying low-level signals, driving loads, and switching circuits in general-purpose electronics.

What is the 2N5550 pinout?

The 2N5550 pinout is Emitter–Base–Collector (E–B–C) when viewed from the flat side.

Is 2N5550 a high-voltage transistor?

Yes, it supports up to 140 V collector-emitter and 160 V collector-base voltage, ideal for high-voltage, low-current designs.

What is the maximum current rating of 2N5550?

It can handle up to 600 mA of collector current safely.

Can I use 2N5551 instead of 2N5550?

Yes, in most circuits, 2N5551 can serve as a direct replacement, but verify the gain and pin orientation before use.

Conclusion

The 2N5550 NPN transistor is a versatile, high-voltage small-signal device that delivers excellent performance in both amplification and switching roles. Its 140 V/160 V breakdown voltages, 600 mA current capacity, and low noise operation make it ideal for audio, control, and driver circuits. Compact, reliable, and easy to integrate, the 2N5550 transistor remains a popular choice among engineers and electronic hobbyists who need stable and durable signal handling in TO-92 packages.

Datasheet & Pinout of 2N5550 NPN Transistor

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