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There is a question about 'Stability of Integrator'

dressler6

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aaaaa.jpg

I need a high performance integrator.
And I want to check 'Stability of the integrator block'.
So I designed it like the figure, and assigned it as the STB instance of SPECTRE at the place labeled VAC and simulated it.
Loop gain and phase margin are shown in the figure.

The area marked in red has a gain greater than 0dB.

Should I only get the "phase margin" in red?
If not, how should we check it?
If you have any good documents, please share them.

Thank you.
 

FvM

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The measurement seems to indicate about 90° phase margin and thus unconditional stability. STB setup looks correct.

The measurement setup seems unreasonably simplified, where's the integrator input and input R. Apparently there's a zero in the loop gain, but no related R.
 

LvW

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The clasic MILLER integrator has a fedback capacitor and a serie resistor between integrator input and the inv. opamp terminal.
Where is this resistor? Otherwise, the loop gain check is wrong!
 

sutapanaki

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How do you provide bias to the negative input?
 

LvW

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At first, it is necessary to show us the complete circuit you are going to use.
 

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