What are the advantages and disadvantages of emitter follower?

What are the advantages and disadvantages of emitter follower?

Emitter follower circuit provides high input impedance and low output impedences. The main advantage of using emitter follower configuration is that it provides a voltage gain of unity..Emitter follower circuit are also named as high input impedance circuit..

Which of the following is a disadvantage of CE amplifier?

It has a tendency to become noisy with age especially in moist climate. The voltage gain reduces at low as well as high frequencies. It provides poor impedance matching and hence it cannot be used as a final stage of an amplifier.

What is disadvantage of CE configuration?

Moreover, CE cannot shunt the RE effectively because of its large reactance at low frequencies. These two factors cause a drops off of voltage gain at low frequencies. At High Frequencies (> FH) The reactance of coupling capacitor C2 is very small and it behaves as a short circuit.

What is the main reason for use of an emitter follower?

The emitter follower is widely used as a buffer amplifier to reduce the loading on the previous stage and provide a lower impedance output for any following circuits.

What will happen if a resistor is added to the emitter of a common emitter amplifier?

The addition of this emitter resistor means that the transistors emitter terminal is no longer grounded or at zero volt potential but sits at a small potential above it given by the Ohms Law equation of: VE = IE x RE.

Why CE configuration is most widely used?

⦁ CE is most widely used because it provides the voltage gain required for most of the day to day applications of preamp and power amps. ⦁ Common emitter is the most basic configuration for amplifier circuits. It also provide the maximum transconductance or voltage gain for a given load.

What are the advantages and uses of an emitter follower circuit?

Emitter follower circuit provides high input impedance and low output impedences. The main advantage of using emitter follower configuration is that it provides a voltage gain of unity ..Emitter follower circuit are also named as high input impedance circuit..Also emitter follower circuit have high current amplification factor.

Is it possible to directly couple an emitter follower?

It is not always possible to directly couple the emitter follower, common collector buffer. When this is the case, it is necessary to add coupling capacitors and bias resistors to the circuit. The emitter follower can be designed using the design flow below as a basis:

How is the resistance of an emitter follower calculated?

As it is normally used as a buffer amplifier, this is the key parameter. The input resistance can easily be calculated for a circuit because it is β times the resistor R1, where β is the forward current gain of the transistor. The simplest way of connecting an emitter follower is to directly couple the input as shown below.

What are the disadvantages of a common emitter amplifier?

Disadvantages of Common Emitter Amplifier. In the high frequencies, the common emitter amplifier does not respond. The voltage gain of this amplifier is unstable. The output resistance is very high in these amplifiers. In these amplifiers, there is a high thermal instability. High output resistance.