How does an emitter follower work?
Emitter Follower. This is an emitter follower or buffer amplifier circuit, where the output is simply equal to the input minus a diode drop (about 700mV). It provides low output impedance to any circuit using the output of the follower, meaning that the output will not drop under load.
Which transistor is emitter follower?
In electronics, a common collector amplifier (also known as an emitter follower) is one of three basic single-stage bipolar junction transistor (BJT) amplifier topologies, typically used as a voltage buffer.
What is the main application of an emitter follower?
The emitter follower configuration is mostly used as a voltage buffer. These configurations are widely used in impedance matching applications because of their high input impedance.
How does a common emitter transistor work?
Operation of Common Emitter Amplifier When a signal is applied across the emitter-base junction, the forward bias across this junction increases during the upper half cycle. This leads to an increase in the flow of electrons from the emitter to a collector through the base, hence increases the collector current.
What is an emitter follower circuit?
An emitter follower circuit is a transistor circuit in which the voltage at the emitter follows the input voltage. The point of an emitter follower circuit is that it can act as a buffer. Since it has a high input impedance and a low output impedance, it mimics the effect of a buffer.
What is the emitter follower circuit?
Emitter follower is a case of negative current feedback circuit. This is mostly used as a last stage amplifier in signal generator circuits. The important features of Emitter Follower are − It has high input impedance. It has low output impedance.
Why it is 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 emitter follower configuration?
Common collector configuration, also known as emitter follower provides high input impedance and low output impedance. So they are used for the purpose of impedance matching. In common collector configuration, the collector terminal is common to both input and output terminals.
What is the function of emitter in transistor?
The emitter supplies electrons. The base pulls these electrons from the emitter because it has a more positive voltage than does the emitter. This movement of electrons creates a flow of electricity through the transistor. The current passes from the emitter to the collector through the base.
What is emitter follower circuit?
Can a common emitter configuration be applied to a PNP transistor?
Common emitter configuration can be applied on both types of transistor, PNP transistor, and NPN transistor. Here we especially talk about common emitter configuration of bjt.
How does an emitter follower transistor amplifier work?
The emitter follower transistor amplifier has a very straightforward circuit. The base is connected to the previous stage, and often this may be directly connected as this can save on additional bias resistors which lower the input impedance and hence increase the loading to the previous stage.
What makes an emitter follower a common collector?
The emitter follower or common collector circuit configuration provides a high input impedance and a low output impedance. This means that the emitter follower circuit provides an ideal buffer stage,…
Which is the best matched PNP for the emitter follower?
For best matching use the SSM2220 matched PNP pair for Q 3 and Q 4 and the SSM2212 matched NPN pair for Q 5 and Q 6 (NPN mirror gain will be 1, add a second SSM2212 in parallel with Q 5 to increase the mirror gain). An alternate approach to improving the emitter follower is to reduce the effective r e through negative feedback.