2N5089 NPN Transistor : Pin Configuration & Its Applications

The 2N5089 transistor is an NPN-based amplifier BJT that works like a switch within saturation mode whereas, in the active region, it works as an amplifier. This is a silicon (Si) based transistor, mainly designed for amplification of the audio signal by enhancing the weak signal to generate a strong output signal at the collector terminal of the transistor within low power systems.


This kind of transistor is extensively used for amplification in audio equipment and this transistor provides collector current like 50mAdc continuously. This article discusses an overview of the 2N5089 NPN amplifier transistor and its working with applications.

What is a 2N5089 Transistor?

2N5089 transistor is a BJT, designed with a TO-92 package by different manufacturers of electronic components. The main reason to design this transistor is to strengthen any kind of signal from low gain to high. Here the signals which are amplified are either analog or digital.

2N5089 NPN Transistor
2N5089 NPN Transistor

Once we amplify a signal from low gain with a normal low noise type transistor then the transistor also increases the noise through the low gain signal because the output received from the transistor is mixed with noise. However, the 2N5089 transistor has a low noise feature with a 2.0 dB noise figure because of the low noise output signal from this transistor.

Alternatively, this transistor can also be utilized like a switch for operating a load below 100mA. In addition, it can also be utilized in RF-based applications below 50MHz frequency.

Pin Configuration

The pin configuration of the 2N5089 transistor along with its symbol is shown below. This kind of transistor is available with three terminals like emitter, base & collector where each terminal with its working is discussed below.

2N5089 NPN Transistor Pin Configuration
2N5089 NPN Transistor Pin Configuration
  • Pin1 (Emitter): This is an emitter terminal of the transistor
  • Pin2 (Base): This is the base terminal of the transistor
  • Pin3 (Collector): This is the collector terminal of the transistor

Features & Specifications

The features & specifications of the 2N5089 NPN transistor include the following.

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  • The available package is TO-92
  • The type of transistor is NPN
  • Collector current (IC) is 100mA
  • Collector to emitter voltage or VCE (Max) is 25V
  • Collector to base voltage or VCB (Max) is 30V
  • Emitter to base voltage or VEBO is (Max) is 3V
  • Collector dissipation or Pc (Max) is 625 mW
  • Transition frequency or fT (Max) is 50 MHz
  • Min & Max gain of DC or hFE ranges from 400 to 1200
  • Storage and operating temperature (Max) ranges from -55 to +150 C
  • Collector current continuously or IC is 50 mA

The equivalent 2N5089 transistor in SMD version is MMBT5089 transistor in SMD version with SOT-23 package, 2N5088, SS9014, BC550, BC548, BC547 & BC549 Replacements of 2N5089 transistor are MPS6532, MPS650, MPSW0, MPSH10, ZTX690B, MPS650, MPSH10, MPSW0 & MPS6532.

Why to Choose a 2N5089 Transistor?

There are many reasons to choose a 2N5089 transistor which include the following.

  • The 2N5089 NPN transistor is appropriate to utilize on the low side switching. Similarly, a PNP transistor is used in any application that needs high side switching.
  • 2N5089 transistor supports 25V of breakdown voltage from collector terminal to emitter & 30Volts of the collector to emitter breakdown voltage.
  • This NPN transistor works with a continuous collector current of up to 50mA.
  • This NPN silicon transistor provides high hFE, so used in particular audio-related products or for audio amplification.
  • This NPN transistor is very useful in switching related applications

How to use 2N5089 Transistor/Circuit Diagram

Generally, the transistor is used as a switch and an amplifier. Here in this application, we are going to discuss how the 2N5089 transistor is used as an amplifier. This circuit is mainly designed in a common emitter configuration because this configuration includes high gain. So this circuit is mainly used for signal amplification.

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Amplifier Circuit using 2N5089 NPN Transistor
Amplifier Circuit using 2N5089 NPN Transistor

In the above circuit, how the 2N5089 transistor is connected in audio devices is shown. the coupling capacitor is ‘C1’ whereas the DC blocking capacitor is ‘C2’, The collector resistor is RC, once the value of this is changed then the circuit’s frequency response will be changed and controls the gain of direct current through controlling the CC or collector current. The resistors used in the above circuit like R1 & R2 work like a voltage divider, used to bias the transistor.

Once the audio input signal is given to the base terminal of the transistor & some voltage is given to the collector terminal of the transistor to switch ON the active mode. So this transistor works as an amplifier.


An audio input signal in the above circuit is an AC signal. The main function of coupling capacitors in the circuit is used for avoiding the distortion of the signals otherwise it will affect the quality of audio by showing high i/p impedance to fewer frequency components.

A capacitor is connected at the output in series to block the needless DC components. Here, the RC resistor is used to control the flow of current at the collector terminal for controlling the amplifier’s gain. So it is responsible for the circuit’s frequency response. Consequently, a weak radio signal after flowing throughout an NPN transistor is obtained like an amplified. This amplified signal is used in less noise & audio amplification-based systems.

Where to use 2N5089 NPN Transistor/Applications

The applications of the 2N5089 NPN transistor include the following.

  • This transistor is used in amplifier systems
  • Switching loads below 100mA
  • Hi-Fi audio systems
  • RF Circuits below 50MHz
  • Push-pull type topologies
  • Audio Pre-amplifiers
  • Controlling of tone
  • Voice Recorders
  • Used in switching based applications
  • Sensor-based circuits
  • Audio Amplifiers
  • Radio Circuits
  • Audio Recorders
  • Audio Amplifier Stages
  • Miscellaneous signal amplification
  • Switching circuits
  • Signals modulation
  • Less noise amplification-based systems
  • High AF systems
  • Temperature detecting systems
  • Push-pull circuits

Please refer to this link to know more about 2N5089 NPN Transistor Datasheet

Thus, the 2N5089 NPN amplifier transistor is based on Silicon, mainly designed to be used for amplification purposes in audio devices. This transistor works in two modes; when this transistor works in saturation mode then it works like a switch. Similarly, when it works in the active region the transistor works as an amplifier. Here is a question for you, what is the function of an amplifier?

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