arunkumar.kunjappan
Newbie level 4
Hi Guys,
I have a RC LPF filter with fc=15.9KHz (R=10K and C=1nF). When I cascaded such two filters to form a second order filter and did an AC sweep, I got the new fc around 6KHz. But if I refer the formula for the fc of a second order filler with
R1=R2 and C1=C2, I should get the same fc (i.e 15.9KHz). Now I intoded a voltage vollower with op amp in between the first stage and second stage. After this I could see the fc changed to around 10KHz. Can anyone explain me the reason behind this behaviour.
Thanks inadvance,
Arunkumar.
I have a RC LPF filter with fc=15.9KHz (R=10K and C=1nF). When I cascaded such two filters to form a second order filter and did an AC sweep, I got the new fc around 6KHz. But if I refer the formula for the fc of a second order filler with
R1=R2 and C1=C2, I should get the same fc (i.e 15.9KHz). Now I intoded a voltage vollower with op amp in between the first stage and second stage. After this I could see the fc changed to around 10KHz. Can anyone explain me the reason behind this behaviour.
Thanks inadvance,
Arunkumar.