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filtercircuit and integrator(opamp) ..... are they same?

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puzzle8

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hey can anybody tell me how a filtercircuit and an integrator made from an opamp are same things.
i mean a filter is used to just filter in the required frequency signals giving the same gain type of signal as given in the input.
whereas an integrator would change thetype of the input. so how can these two systems synonyms.
 

From a point of view the integrator can be considered as a low pass filter.
Assuming a law pass filter has a transfer fn. H(s) = 1/(1+ s/ ωp).

As it is known from the s-domain to integrate means to multiply by 1/s
So the integrator can be considered as low pass filter that has corner frequency at 0Hz.
 

for this u can get answer from integrated electronics by millman
 

puzzle8 said:
hey can anybody tell me how a filtercircuit and an integrator made from an opamp are same things.
i mean a filter is used to just filter in the required frequency signals giving the same gain type of signal as given in the input.
whereas an integrator would change thetype of the input. so how can these two systems synonyms.
schematic wise similar
 

puzzle8,
You can think of an integrator as a low pass filter with a corner frequency of zero. Its gain at zero frequency is infinity. Its transfer function is f(s) = 1/((Tau)s). The transfer function of a single ple low pass filter is f(s) = K/(1+(Tau)s). Dividing numerator and denominator by Tau yields f(s) = (K/Tau)/((1/Tau) + s). At zero frequency(s=0), its gain is K.
Regards,
Kral
 

The integrator is actually a LPF whether it was made by passive or active components. When you apply a square wave to an integrator, you actually remove the higher frequencies of this square wave, leaving the the lower frequencies which give you the triangular wave. I mean that the integrator removes the fast transition in the square wave keeping the slow ones.

Hope this helps.
Please, comment if I'm wrong.
 

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