Electronics Engineering
Electrical Engineering

What is the function of a bypass capacitor in an amplifier?

Top Answer
User Avatar
Wiki User
Answered 2010-12-16 14:16:59

Bypass capacitors are used to bypass (shunt) unwanted signals to the ground. A common use is in power supplies where a bypass capacitor is connected in parallel with the main filter capacitor to shunt noise and other high frequency interference to ground which the main capacitor may not be able to do.

User Avatar

Your Answer

Still Have Questions?

Related Questions

What is Common Emitter Amplifier with emitter bypass capacitor?

The amplifier gain characteristics will change due too the bypass of AC signal to ground by the capacitor

What will happen to the voltage gain of the amplifier circuit when you remove the bypass capacitor?

If you remove the supply bypass capacitor, chances are the amplifier just won't work. If you remove the emitter bypass capacitor of the amplifier, DC gain remains unaffected while AC gain increases within the passband. Note though, that the passband is affected by removing/adding the emitter bypass capacitor. Hope this helps :)

What is the bypass capacitor polarity in transistor amplifier?

a bypass capacitor is capacitor whose one end is grounded it is used to short the resistor if it is parallel to the capacitor used for dc analysis

How is the gain of an R-C coupled amplifier affected if the emitter-bypass capacitor is removed?

The emitter bypass capacitor, in a typical common emitter configuration, increases gain as a function of frequency, making a high pass filter. Removing the capacitor will remove the gain component due to frequency, and the amplifier will degrade to its DC characteristics.

How is gain affected by a source bypass capacitor?

The addition of a bypass capacitor in parallel with the source resistor raises the gain of an amplifier but makes it less predictable.

What is the function of emitter bypass capacitor in common emitter amplifier?

The emitter bypass capacitor in a common emitter amplifier will have less resistance as the frequency increases. Since gain in this configuration is collector resistance divided by emitter resistance (within limits of hFe), the gain will thus increase for higher frequencies, making this into a high pass filter.

What is purpose of emmiter bypass capacitor in R-C coupled amplifier?

Emitter bypass capacitor is a capacitor which provide low impedance to AC and high impedance to DC . AC is shunt then only DC appears on RC and volage gain increses.

Why don't use bypass capacitor in common collector?

You would use a supply bypass capacitor in a common collector amplifier... It's necessary, to give the positive supply rail a direct AC connection to ground. Without it, I don't think the amplifier would work properly. However, if you're using a power supply and not a battery, then chances are that it HAS a big capacitor inside it, eliminating the need for any external capacitor.

What is the effect on voltage gain in a common emitter amplifier when the decoupling capacitor is removed?

A: The emitter decoupling capacitor sole function is to increase gain at hi frequency

What is the effect of emitter bypass capacitor?

It routes the AC signal to ground, maintaining a constant DC at the emitter, thereby increasing amplifier gain and stability.

Why is gain affected when the bypass capacitor is open?

Applied input signal at the base of the amplifier appears across the emitter resistor (RE) due to inter electrode capacitance so it should be bypassed the emitter resistor (RE) through the bypass capacitor (CB). unbypassed signal will be amplified (common emitter amplifier) and reverse back from the emitter to the collector through the base, amplified signal from the emitter to the collector (common emitter amplifier) is 1800 out of phase to the amplified signal from the base to the collector (common base amplifier), so reduced the gain.

What is effect of emitter-bypass capacitor on frequency response?

Gain in a CE configuration of a BJT is collector resistance divided by emitter resistance, subject to the limit of hFe. The emitter bypass capacitor will have lower impedance at high frequency, so the gain will be higher at higher frequency, making this a high-pass amplifier.

When capacitors are used to shunt current across components such as resistors they are called?

A capacitor is typically placed across a resistor for the purpose of shunting either the AC component of a current (as in a transistor amplifier) or transient AC 'spikes', and is referred to as a "bypass capacitor".

Loading effect in RC coupled amplifier?

Loading of Rc coupled amplifier occurs, if you doesnt use coupling capacitors...... If avoiding input coupling capacitor the amplifier will load the function generator.. For more details go to http://mycircuits9.blogspot.com

What is the effect of bypass capacitor on frequency response?

At loer frquency, the bypass capacitor ce is not short, the emitter is not at ac ground xc in parrllel with re.

Purpose of power capacitor bank in car stereo?

hi guys,use of capacitor in car stereo amplifier is really helpful..specially when using an amplifier(s) to drive speakers.the purpose of capacitor is to maintain current level for amplifier(s) so it can perform better and give optimum performance to the speakers. Power capacitor uses the current from main battery and stores it in itself. and whenever car is turned off, amplifier uses the stored power from capacitor.. hopefully this answer will be helpful.

Why does the emitter bypass capacitor in the common emitter amplifier increase the voltage gain?

The emitter bypass capacitor creates an alternate path for AC only with much less resistance while still leaving Resistor RE present in the circuit to preserve the division of DC voltage. With less resistance acting on the AC signal it performs at a much higher level.

What is the difference between voltage gain obtained with bypass capacitor and without the bypass capacitor?

A: A TRANSISTOR gain is determined by current flow on the collector by adding a resistor to the emitter this current flow is reduced by adding or bypassing this resistor with a capacitor the net effect is that this emitter resistor will be reduced in value as frequency increases therefore change gain as a function of frequency input

Why coupling capacitor is used between two stages of a feedback amplifier circuit?

if we want to stop the dc voltage and pass the ac signal we must use coupling capacitor in an amplifier....

Why we use blocking and by pass capacitor in CE amplifier?

As the DC component in the signals are not required to be amplified, rather not required at times. Thus a blocking capacitor blocks this DC component from.entering the amplifier. Bypass capacitors are used at the emitter end so that the AC signal reaching the emitter end does not alter the biasing required to maintain the Q-point. All the above happens using the basic characteristic of a capacitor, that it blocks DC and passes AC.

Why bypass capacitor is used in common emitter ampifier circuit?

If a bypass capacitor is used the voltage drop across emitter resistance is reduced which in turn increases the gain.....

What effect does the bypass capacitor have on the output impedance of the amplifier?

The quantity of specific information included in the question is exceeded only bythe quantity of vital, relevant information that's never mentioned.Are you talking vacuum-tube or transistor amplifier ? What's the configuration of theamplifier, i.e., which terminal of the active device is 'common' to input and output ?And where is the bypass capacitor in the circuit ?I'll take a wild stab and assume that you have a common-emitter amplifier, with thecapacitor bypassing the bias resistor in the emitter branch. If that's the case, thenthe resistor is supposed to be there only to set the DC Q-point, but every effect itcould have on small-signal performance would be an effect that you don't want ...it would increase the output impedance, and any impedance common to input andoutput always reduces the gain.So one of the effects of the bypass capacitor is to reduce the output impedanceof the stage.(If Dingobot comes along now and flags this for gibberish, that'll be my first cluethat after all these years, I don't actually remember this stuff too well.)

Still have questions?

Trending Questions
How to Make Money Online? Asked By Wiki User
Best foods for weight loss? Asked By Wiki User
Does Neil Robertson wear a wig? Asked By Wiki User
Unanswered Questions