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S8550 Transistor: A Detailed Explanation

Transistors are semiconductor devices used to either amplify or generate electrical signals. Therefore, they can work on either direct current or alternating current applications applications applications applications. This article will help you learn more about the s8550 transistor. 

What is the S8550 transistor?

The S8550 transistor is an example of a PNP transistor. 

A PNP Transistor

A PNP Transistor

The s8550 is so thatter stay open during reverse bias. That’s known as a grounded sta during reverse bias during reverse bias during reverse biaste. In contrast, during forwarding bias, the base pin receives a signal.

The S8550 transistor allows a maximum load current of 700mA when entirely biased. We refer to that point as the saturation region. In contrast, withdrawal of the base current turns the transistor off. A point called the cut-off. 

The s8550 transistor has a gain value of 300 thus has a high amplification capacity.

The transistor falls under the Class B amplifier. Therefore, it can amplify low signals to the desired gain output stage of various audio systems.

s8550 transistor Pin Configuration

S8550 Pin Configuration

S8550 Pin Configuration

The S8550 has three pins, namely:

  • Emitter
  • Base
  • Collector

The emitter is the current source, while the base provides for the ON and OFF of the transistor. On the other hand, the collector pin allows for current flow to the output load. 

The Features and Specifications

It is usually used as a push-pull amplifier and in switching applications. It is so since it is a low voltage and high current transistor.

The S8550 is a high current, low voltage PNP transistor. 

In addition, it has a Collector Base voltage (VCB0) of -40V and an Emitter-Base voltage of (VBE0) of -5V.

On the other hand, its Collector-Emitter voltage (VCE0) is -25V, while its Current Gain ranges between 85 and 300. 

Lastly, it is usually available in TO-92, with a continuous collector current of 500mA.

s8550 transistor Alternatives

  • BC527
  • S8050
  • 2N2906
  • BC528


An Audio Amplifier

An Audio Amplifier

  • As an mp3 audio amplifier
  • The output of buzzer circuits, electronic doorbell circuits, etc.
  • As an output for various small electronic projects


The s8550 is an example of a PNP transistor‘’ used in various digital electronics applications. It’s also used to execute simple electronic projects involving AC Circuits or DC Electric Circuits. Some widely used cases are audio amplifier circuits and driving loads below 700mA.

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