If the second stage does not load the first stage, then a two real pole rc filter will be 6 dB down. However if the second stage does load the first stage, then there is additional attenuation at the cutoff frequency. If the R's and C's are equivalent in the two filters, then it ends up being 9 dB down.
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If the second stage does not load the first stage, then a two real pole rc filter will be 6 dB down. However if the second stage does load the first stage, then there is additional attenuation at the cutoff frequency. If the R's and C's are equivalent in the two filters, then it ends up being 9 dB down.
I want a 20 dB down, and then a zero, and again a pole who does 40 dB down. Is there some info about that and make it with opamps. Thanks.