Characteristic Curves of a Transistor

A transistor operates the electric current or voltage. It ordinarily acts as a gate for digital indicators. Transistors incorporate three layers of semiconductor entities, where each one can carry electric current.

Three well-known scientists are liable for the ingenuity of transistors. It promptly renovated the vacuum tube as a digital signal regulator. A transistor oversees electric current and gush of voltage and pretends as a transfer or gate for electronic alerts. A transistor embodies three layers of semiconductor entities. And each one has the proficiency to transmit an electric current. A semiconductor is a substance envisioned of germanium and silicon that administers electricity in a “semi-enthusiastic” manner. It is relatively between a real conductor with copper and an insulator.

Characteristic curves of a Transistor

Transistor Characteristics primarily exemplify the association between the current and the voltage of identical, and you can analyse the circuits by expensing three classifications of characteristic curves. They are-

1. Input Characteristics:  The differences in the input current values are interpreted concerning the values of input voltage with a constant output voltage in this specification.
2. Output Characteristics: In this characteristic curve, the output current is designed against the output voltage with a constant input current.
3. Current Transfer Characteristics: This characteristic curve exemplifies the output current variation and the input current with a constant voltage.

Configuration Of a Transistor:

A transistor circuit is designed using three types of configuration. Three configurations are based on the connection of the transistor terminal. Types of transistor circuit configurations are mentioned below:

1. CE type
2. CB type
3. CC type

These circuit configurations have their characteristic curve. 

Common Emitter (CE) Configuration of Transistor

In this certain category of configuration, a transistor’s Emitter terminal pertains between the output and the input terminals.

1. Input Characteristics:

It is distinguished as the deviation of emitter current with the base-emitter PNP with a constant emitter voltage.

      Rin=(VBE/IB) , VCE=constant

2. Output Characteristics: The collector current is altered in this arrangement, with the collector voltage keeping the base current constant.

      Rout=VCE/IC  ,   Ib is constant.

3. Current Transfer Characteristics: It is known as the fluctuation in collector current and the base current with a constant collector-emitter voltage supply. In this process, the value of current is greater than 1.

          =IC/Ib  ,  VCB is the constant

Common Base (CB) Configuration of Transistor

In this type of configuration, pnp transistors can pertain between the output and the input terminals.

Common Collector (CC) Configuration of Transistor:

In this type of configuration, the Collector terminal of the transistor is connected between the output and the input terminals.

 Semiconductor junction Transistor

Consider a PNP transistor construction. In this construction N-type silicon semiconductor is kept in between two P-type materials. P+ refers to the highly doped P-type material. This doped portion is referred to as Emitter and it is the piece of semiconductor that supplies majority carriers for the transistor functioning. On the other side, there is a moderately doped P-type Collector. In this portion, the majority charge gets collected and the carriers emitted by Emitter. This helps to cross the collector. The middle region is represented by n- as it is doped with N-type impurities. ‘-‘ sign indicates less doped compared to the emitter and collector. The middle region is the Base, which serves as a gate. It regulates the flow of charge from the Emitter to the collector.

The doping in the base region is just one-tenth of the collector region. In the case of real transistors, the width of the base is very thin, and the total width of the transistor becomes 150 times the width of the base.

Importance Of transistor Characteristics

Pnp Transistors can be wielded for overstating, regulating, and producing and, it encompasses umpteen minuscule devices inscribed into their glossy surfaces. Thus the purposes furnished by transistors consist of switching of electronic signals and overstating the electronic signals. A transistor can also be expended as a small signal applied between two terminals helps control a much larger signal at another two terminals. This property is known as gain. A stronger output signal Is produced with voltage or current and is proportional to a weaker input signal and thus, acts as an amplifier.

Conclusion

During operating a transistor, the emitter-base junction is set forward-biased. At the same time the collector-base junction is set in reverse-biased.In np-n junction transistors, you can find a large number of electrons in the emitter and many holes in the base region. In np-n transistors, the middle layer is extra thin (〜 1 micrometre) compared to the widths of the two layers present at the sides. Transistors are used as digital and analogue circuits as switches.

Transistors are also used in signal amplifier devices. Cellular phones also use transistors. Every cell phone has a transistor amplifier. Transistors are used in power regulators and controllers. Hope you liked this article! Visit again.