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Which configuration of BJT is emitter follower?
common collector circuit configuration
Transistor Circuit Design Tutorial Includes: The common collector circuit configuration is more widely known as the emitter follower and it provides a high input impedance and a low output impedance.
Which configuration is used for emitter follower?
Common Collector transistor configuration
In the Common Collector transistor configuration, we use the collector terminal as common for both input and output signals. This configuration is also known as emitter follower configuration because the emitter voltage follows the base voltage.
Which configuration is used in BJT?
The three basic configurations of a BJT are (a) common emitter (CE), (b) common base (CB), (c) common collector (CC) or emitter follower. These basic configurations are shown in Figure 1.
Why is it called emitter-follower?
Because of this behavior, the common-collector amplifier circuit is also known as the voltage-follower or emitter-follower amplifier, because the emitter load voltage follows the input so closely. The output is the same peak-to-peak amplitude as the input.
What is the value of gain in emitter-follower?
approximately unity
The emitter follower (Figure 5.11(a)) is a buffer stage with high input impedance, low output impedance, and a gain of approximately unity.
Why emitter follower is used?
Emitter follower is a negative current feedback circuit. Emitter follower configuration, also known as Common collector, provides high input impedance and low output impedance. So they are used for the purpose of impedance matching. This is mostly used as a last stage amplifier in signal generator circuits.
When is an emitter-follower used in a BJT circuit?
In a BJT configuration when the emitter terminal is used as the output, the network is called an emitter-follower. In this configuration the output voltage is always a shade lower than the input base signal due to the inherent base to emitter drop. In simple terms, in this type of transistor circuit the emitter seems to be following
What kind of transistor has an emitter follower?
An emitter follower is one of the standard transistor configurations which is also referred to as common collector transistor configuration. Let’s try to first understand what’s an emitter follower transisto r and why it’s called a common collector transistor circuit.
Where does the output signal come from in a BJT?
The input signal is fed across the base and emitter of the BJT, and the resulting output signal is derived across the base and the collector terminals of the BJT. The base signal is always referenced to the emitter terminal and its potential level.
Why does a BJT circuit behave like an amplifier?
A common base BJT circuit behaves like a non-inverting amplifier circuit, due to the fact that its output signals is always in-phase with the input signal, meaning the output precisely replicates the input signal’s polarity without changing its attributes.