I was trying to compare the differences between passive and active filters and below is for almost same cut off and by using an ideal opamp:
But then I used a real opamp LM324 and obtain the following outputs:
And for the same circuit if I switch to an opamp called LMC6482 I obtain the following output:
Why with real opamps there is such loss in voltage values or power at very very low freq. unlike in ideal case? Is that something related that Im using single supply? Does the vertical axis show peak-to-peak voltages or amplitudes in LTspice? And why two real opamps give totally different loss?
The opmap is clipping yes, but why is the amplitude is 0.6V at 0.2Hz in Bode plot which is 1V in transient analysis. And for LMC6482 the amplitude is 0.1V at 0.2Hz in Bode plot which is 1V in transient analysis. There must be a meaning behind these numbers (?) in Bode plots