Problem with calculating zeros of some Opamps

[tomandrosea]

bais op-amp

Hi everyone :
I try to analysis the poles and zeros of some op amp , for example op07,op27,
but I just can calculate the poles , but I don't know ,how to get the zeros.
Is there some one can help me ? Or maybe give some clues /informations on
those old op amp 's frequency compensation .
The attchment file is op07's datasheet , in it there is the op07's schematic,
this op amp haves 4 Capicitor and 3 poles and 3 zeros.

 

[laglead]

Re: op amp compensation

Hi everyone :
I try to analysis the poles and zeros of some op amp , for example op07,op27,
but I just can calculate the poles , but I don't know ,how to get the zeros.
Is there some one can help me ? Or maybe give some clues /informations on
those old op amp 's frequency compensation .
The attchment file is op07's datasheet , in it there is the op07's schematic,
this op amp haves 4 Capicitor and 3 poles and 3 zeros.

For zeros, I think u should notice the path where signal goes through cap coupling instead of active device. Capacitor coupling can elevate signal gain at high frequency: that is what zero does.

 

[tomandrosea]

Re: op amp compensation

I think it is hard to get the first zero by sovling the equations . I tried several
times , but the process was so laborious . But by some simplification ,
the second zero is easily got . So I really mean , how to get the first
zero without solving the node voltage equations . Or is there some formula
to use ?

 

[beckchm]

Re: op amp compensation

you can simulate the circuit to get the information

 

[pixel]

Re: op amp compensation

Yes, you can easily see zero in the phase response.

 

[wjlzhx]

op amp compensation

I SEE SOME ERROR IN THE schematic ,SOME BASE HAS NO BAIS