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A: Well for one thing if it is positive feedback the amplifier will saturate to one one side of the power buss or the other. An operational amplifier open loop gain can be 90Db which a tremendous gain so some negative feedback is necessary to reduce the gain and make the amplifier behave in the linear region for amplification
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∙ 13y ago
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∙ 13y agoA: An op amp to be stable must have some negative feedback. If the feedback is positive then it can become an oscillator.
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∙ 10y ago1>Noise is decreased .
2>distortion is decreased.
3>BW is increased. 4>The amplification of the amplifier can be decided by external circuit.
Wiki User
∙ 10y agoTo reduce the output signal's distortion
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Difference between amplifier and feedback amplifier?
An ordinary amplifier can have high gain but is unstable, drifts, can oscillate, etc. An amplifier with negative feedback has lower gain but is stable, does not drift, won't oscillate, etc.
Can negative feedback amplifier work as a oscillator if yes how if no why?
All negative feedback systems, whether they be electronic, biological, or anything else, work by applying a negative feedback to the source signal, which is proportional in some way to the source signal. If the factor by which the amplifier corrects is high enough, oscillation will result (perhaps even runaway oscillation) How you make it happen depends upon the amplifier you use however -- though most work similarly enough. You could use a delay between output and feedback, or you could rely on a large amplifier gain.
Why open loop configuration of opamp not used in linear applications?
Open loop means max amplification of an amplifier. if the open loop is very it will probably oscillate since there is not a feedback to control it or it will go to one rail of the other saturated
What is the meaning of gain in an amplifier or operational amplifier. Is high gain or low gain is what we try to achieved?
There are many uses for amplifiers. Some try to achieve extremely high gain such as in a radio receiver. Many try to achieve no overall gain. Examples include mixers and filters. Some only try to achieve limited gain. Oscillators try to achieve zero gain at most frequencies but unity to very high gain at the frequency of oscillation depending on the output wave form required. Basically - everything in electronics is an amplifier. The absolute gain of am amplifier is the ratio of output signal to input signal. For voltage or current amplifiers this is usually expressed as field decibels which is 20 log (out/in). For power amplifiers the gain in decibels is 10 log (output power/input power). If the gain is less than one, the same rules apply but the decibels will turn out to be a negative quantity.
Which coupling gives high gain in case of amplifier?
no.transformer coupling gives higher gain
Why negative feedback is preferred in amplifier?
Because the feedback of an amplifier tends to reduce the gain of an amplifier and also, the bandwidth of feedback increases the gain of an amplifier, so in an high gain amplifier as to be stabilized. BY ENGINEER MUHAMMED OLALEYE OLUWATOSIN TELECOMMUNICATION STUDENT, RUFUS GIWA POLYTECHNIC, OWO
Difference between amplifier and feedback amplifier?
An ordinary amplifier can have high gain but is unstable, drifts, can oscillate, etc. An amplifier with negative feedback has lower gain but is stable, does not drift, won't oscillate, etc.
Can negative feedback amplifier work as a oscillator if yes how if no why?
All negative feedback systems, whether they be electronic, biological, or anything else, work by applying a negative feedback to the source signal, which is proportional in some way to the source signal. If the factor by which the amplifier corrects is high enough, oscillation will result (perhaps even runaway oscillation) How you make it happen depends upon the amplifier you use however -- though most work similarly enough. You could use a delay between output and feedback, or you could rely on a large amplifier gain.
Why neutralisation is used in tuned amplifier?
neutralization is one of the methods to make the amplifier unilateral i.e. to remove internal feedback of the amplifier. It is done to obtain the maximum gain from an amplifier.
Is it possible that an amplifier without feedback may oscillate at high frequency?
it all depends on its open loop gain or crossing the zero db point at slope less the -1db
Why open loop gain of op-amp is very high?
A; An ideal op amp should have infinite open loop gain so when the loop is closed with negative feedback it will be stable
Why gain is fall at high frequency in r-c coupled amplifier?
The gain of an r-c coupled amplifier falls at high frequency because the capacitive reactance of the capacitor tends to zero.
Why common emitter is considered as best?
b'cose the gain of the amplifier is high ..
What is the theory of voltage series feedback amplifier?
In a Voltage Shunt feedback Amplifier, the feedback signal voltage is given to base of transistor in shunt through a feedback resistor.This Shunt connection decreases the input input impedance and voltage feedback decreases the output impedance. In this amplifier input is current and output is voltage. Thus Transresistance is stabilized.Input and Output impedances are reduced by a factor of 'D'(desensitivity factor). Advantages: 1)Gain independent of device parameters. 2)Bandwidth increases. 3)Noise and non-Linear distortion decrease. 4)Prevents Loading effect. 5)Acts as good source for the next stage.
Why open loop configuration of opamp not used in linear applications?
Open loop means max amplification of an amplifier. if the open loop is very it will probably oscillate since there is not a feedback to control it or it will go to one rail of the other saturated
Why does a CE amplifier have a high gain?
GAIN is a function of load current but basically a small current in the base will make a big change of collector current therefore making a transistor a voltage amplifier as opposed to a current amplifier
Advantages of common source fet amplifier?
Due to high input impedence curret gain is high
