Dear friends, what is C2 doing in the picture

[qq91816]

Dear friends, please ask why C2 capacitor is in the picture.

What role does it play?

 

[JMFahey]

Post C2 value or your question makes no sense.

 

[qq91816]

Post C2 value or your question makes no sense.

I wonder if this C2 is wrong?

 

[ej25awd]

C2 is likely for boosting high frequency and it can cause instability on some op amps.

 

[qq91816]

C2 is likely for boosting high frequency and it can cause instability on some op amps.

I saw a power amplifier using LME49830 adding C2 to the feedback circuit. I think maybe this is a mistake.

 

[Veysel]

Itz boosting high freq

 

[jan.didden]

This is often used to increase stability by compensating for parasitic capacity for instance on the +inp or the output.
It normally has no impact on the freq response because the RC time with it's resistor is way above the circuit bandwidth.

Mostly in the single pF range, or maybe up to 22p.

Jan

 

[qq91816]

Itz boosting high freq

But will it cause circuit oscillation?

 

[jan.didden]

Only if overdone, or when you roll opamps. Keep the recommended value (unless this is a diy schematic, in that case all bets are off).

Jan

 

[qq91816]

Only if overdone, or when you roll opamps. Keep the recommended value (unless this is a diy schematic, in that case all bets are off).

Jan

Sorry, my English is poor and I don't understand it very well.(unless this is a diy sche matic, in that case all bets are off).

What will happen if C2 exceeds 100 pf?

 

[qq91816]

I'm curious about why engineers will add C2 capacitor as a demonstration.

It said it would improve the effect.

 

[qq91816]

I wonder why TI engineers want to add the C13 capacitor.

 

[qq91816]

TI Description Document：


FIGURE 6. Gain And Low Frequency Response
Experimentation with high quality film capacitors in these locations may result in additional sonic improvements. Such
investigation is not covered in this document.

C13 sonic improvements. ？？？

 

[DF96]

Your question has been answered. The capacitor boosts high frequencies, and affects stability. What else is there to say?

 

[Osvaldo de Banfield]

What else is there to say?

That in this position "only high quality capacitors" must be used :-D

 

[qq91816]

Your question has been answered. The capacitor boosts high frequencies, and affects stability. What else is there to say?

Thank you, my friend.



I just want to make sure that this capacitor is an incorrect demonstration.

 

[qq91816]

Excuse me. Is the C2 on the graph a pole compensation capacitor?

Excuse me. Is the C2 on the graph a pole compensation capacitor?

Does it stabilize the circuit?

 

[Osvaldo de Banfield]

Once again? This question has already been done and solved.

 

[qq91816]

Once again? This question has already been done and solved.

Sorry, I may have doubts on this issue.

I was told that C2 is a "dominant pole compensati" capacitor and that it stabilizes the circuit？？

But you said it would lead to circuit instability
.

I'm sorry to disturb you.

 

[Osvaldo de Banfield]

Ignoring the effect of the big electrolytic capacitor, the amp has a DC gain of 1 (0dB) which essentially continues until the unknown reactance of unknown value of C2 equals the resistance in parallel with it. This will be the corner frequency of +3dB, an if you continue increasing frequency, the amp theoretically reaches infinite gain, only limited by the opamp ihnherent gain.

This is how the schematic works in few and simple words.