I have a voltage signal (represents velocity of a beam) and I want to integrate it to get the displacement.
the frequency range is from 20 to 60 KHz
I used the standard integration circuit.... opamp with resistor and a capacitor at the feedback.
I used a sinusoidal zero mean input, and the peak to peak output was always correct but there was always a dc shift (sometimes up and sometimes down)
up means that the maximum of the sine wave is 15 and when I decrease the amplitude of the input the input of the output decreases but keeping the maximum at 15 (not exactly 15 but I mean at upper maximum of the range of the opamp output)
the output is consistent for a given amplitude and frequency ( I power off every thing and ground every thing and I get the same exact results)
I tried a wide range of opamps,
I tried also putting a large resistance across the capacitor( this made the output mean constant but not at zero)
I tried balancing input current but it didn't improve anything
thanks alot
the frequency range is from 20 to 60 KHz
I used the standard integration circuit.... opamp with resistor and a capacitor at the feedback.
I used a sinusoidal zero mean input, and the peak to peak output was always correct but there was always a dc shift (sometimes up and sometimes down)
up means that the maximum of the sine wave is 15 and when I decrease the amplitude of the input the input of the output decreases but keeping the maximum at 15 (not exactly 15 but I mean at upper maximum of the range of the opamp output)
the output is consistent for a given amplitude and frequency ( I power off every thing and ground every thing and I get the same exact results)
I tried a wide range of opamps,
I tried also putting a large resistance across the capacitor( this made the output mean constant but not at zero)
I tried balancing input current but it didn't improve anything
thanks alot