with the help of circuit diagram explain how transistor can be used as amplifier in common configuration
Answers
Answer:
Explanation:
A transistor is a three terminal semiconductor device, and the terminals are E(Emitter), B (Base) & C (Collector). The transistor can work in three different regions like active region, cutoff region & saturation region. Transistors are turned off while working in the cut-off region and turned on while working in the saturation region. Transistors work as an amplifier while they work in the active region. The main function of a transistor as an amplifier is to enhance the input signal without changing much. Here this article discusses how a transistor works as an amplifier.
Transistor as an Amplifier
Amplifier circuit can be defined as, a circuit which is used to amplify a signal. The input of the amplifier is a voltage otherwise current, where the output will be an amplifier input signal. An amplifier circuit which uses a transistor otherwise transistors is known as a transistor amplifier. The applications of transistor amplifier circuits mainly involve in audio, radio, optical fiber communication, etc.
The transistor configurations are classified into three types such as CB (common base), CC (common collector), and CE (common emitter). But common emitter configuration is frequently used in the applications like an audio amplifier. Because in CB configuration, the gain is <1, and in CC configuration, the gain is almost equivalent to 1.
The parameters of a good transistor mainly include different parameters namely high gain, high slew rate, high bandwidth, high linearity, high efficiency, high i/p impedance, and high stability etc.
Transistor as an Amplifier Circuit
A transistor can be used as an amplifier by enhancing the weak signal’s strength. With the help of the following transistor amplifier circuit, one can get an idea about how the transistor circuit works as an amplifier circuit.
In the below circuit, the input signal can be applied among the emitter-base junction and the output across the Rc load connected in the collector circuit.
For accurate amplification, always remember that the input is connected in forward-biased whereas the output is connected in reverse-biased. For this reason, in addition to the signal, we apply DC voltage (VEE) in the input circuit as shown in the above circuit.
Generally, the input circuit includes low resistance as a result; a little change will occur in signal voltage at the input which leads to a significant change within the emitter current. Because of the transistor act, emitter current change will cause the same change within the collector circuit.
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At present, the flow of collector current through an Rc generates a huge voltage across it. Therefore, the applied weak signal at the input circuit will come out in the amplified form at the collector circuit in the output. In this method, the transistor performs as an amplifier.
