14 Difference between NPN and PNP Transistors | Similarities

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In this article, we are going to study about what is the difference between PNP and NPN transistors with multiple specifications and their symbolic representations.

Let’s compare both transistors in tabular form.

Difference between NPN and PNP Transistors

#ContentNPN TransistorPNP Transistor
01NPN & PNP transistors full formThe NPN transistor stands for the ‘negative positive negative’ transistor.The PNP transistor stands for the ‘positive negative positive’ transistor.
02Transistor constructionThe NPN transistor is a semiconductor device that consists of a single P-type layer and two N-type layers of semiconductor.The PNP transistor is a semiconductor device that consists of a single N-type layer and two P-type layers of semiconductor.
03Emitter & Collector From the N-type materials, emitter and collector terminals of the NPN transistor are formed.From the P-type materials, emitter, and collector terminals of the PNP transistor are formed.
04BaseThe base terminal is made of P-type material. The base terminal is made of N-type material.
05Majority charge carriersThis transistor contains a large number of electrons. This transistor contains a large number of holes.
06Minority
charge carriers
The minimum number of holes is present.The minimum number of electrons is present.
07Current strategyIn the NPN transistor, current flows from the collector (C) terminal to the emitter (E) terminal.In the PNP transistor, current flows from the emitter (E) terminal to the collector (C) terminal.
08Base TerminalThe NPN transistor requires a high signal at the base terminal.The PNP requires a low signal at the base terminal.
09Working RoleWhen the positive (i.e. high signal) connects to the base terminal of the NPN transistor, the NPN transistor is activated.When the ground (i.e. low signal) connects to the base terminal of the PNP transistor, the PNP transistor is activated.
10SensorsSometimes, the NPN transistors are called ‘Sinking sensors’.The PNP transistors are called ‘Sourcing sensors’.
11Applications (Usage)The NPN transistor is widely used, due to the presence of electrons as the majority charge carriers. The PNP transistor is not much used as compare to the NPN transistor.
12Use of NPN & PNP TransistorsIt is used for fast switching in electronic circuits or gadgets. It is used for low switching in electronic circuits or gadgets.
13Operating TimeIt requires less time for switching operations as compared to the PNP transistor.It requires more time for switching operations as compared to the NPN transistor.

14. Symbol of NPN and PNP transistors

The symbolic structures of NPN and PNP are almost the same. But, the current direction is different.

NPN transistor Symbol:

In the NPN transistor symbol, the emitter terminal represents by the outward arrow.

PNP transistor Symbol:

In the PNP transistor symbol, the emitter terminal represents by the inward arrow.

This is all about the NPN vs PNP transistors.

It concludes that the main difference between NPN and PNP transistors is the use of biasing and current directions. Otherwise, both transistors have similarities.

Similarities of NPN Transistor and PNP Transistor

The NPN and PNP transistors are the parts of the bipolar junction transistor (BJT).

  • The NPN and PNP transistors are semiconductor components of BJT.
  • Both transistors are made up of P-type and N-type semiconductors.
  • These two transistors work as current-controlled devices.
  • The emitter (E), base (B), and collector (C) terminals are the same in BJT (i.e. NPN & PNP transistors).
  • In electrical and electronics circuits, both NPN and PNP transistors are more capable to perform amplification and switching operations.

If you have any queries regarding the NPN vs PNP transistors, you can ask by commenting below.

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