SneaKSz
Member
Hi all,
I'm struggling with the following opamp circuit which acts like a filter :
![Capture.JPG Capture.JPG](https://www.electro-tech-online.com/data/attachments/47/47477-dcf45ec40593685b1860fee359f32b98.jpg)
H=1+ Z2/Z1
Z1 = R2+1/sC2 = (s.C2.R2+1)/sC2
Z2 = (R1/sC1)/(R1+1/sC1)= (R1/sC1)/((s.C1.R1+1)/sC1)= R1/(s.C1.R1+1)
H= 1+R1/(s.C1.R1+1) / (s.C2.R2+1)/sC2 =1+ (R1*sC2)/((s.C1.R1+1)*(s.C2.R2+1))
and now things are about to heat up!
H=1+ (R1*sC2)/((s.C1.R1+1)*(s.C2.R2+1)) = (((s.C1.R1+1)*(s.C2.R2+1)) + (R1*sC2))/((s.C1.R1+1)*(s.C2.R2+1))
So the denominator is fine now = (s.C1.R1+1)*(s.C2.R2+1)
now the numerator : (s.C1.R1+1)*(s.C2.R2+1) + (R1*sC2) = s.C1.R1.C2.R2+s.C1.R1+s.C2.R2+1+R1*sC2
now the options are :
: s.C2.(R1+R2)+s.C1.R1.C2.R2+s.C1.R1+1
: s.R1.(C1+C2)+s.C1.R1.C2.R2+s.C2.R2+1
:s.R1.C2(1+s.R2.C1)+s.C1.R1+s.C2.R2+1
none of them can lead to a result as = X( 1+s.CxRx)(1+s.CxxRxx)
Someone who sees something I'm unable to?
Cheers
I'm struggling with the following opamp circuit which acts like a filter :
![Capture.JPG Capture.JPG](https://www.electro-tech-online.com/data/attachments/47/47477-dcf45ec40593685b1860fee359f32b98.jpg)
H=1+ Z2/Z1
Z1 = R2+1/sC2 = (s.C2.R2+1)/sC2
Z2 = (R1/sC1)/(R1+1/sC1)= (R1/sC1)/((s.C1.R1+1)/sC1)= R1/(s.C1.R1+1)
H= 1+R1/(s.C1.R1+1) / (s.C2.R2+1)/sC2 =1+ (R1*sC2)/((s.C1.R1+1)*(s.C2.R2+1))
and now things are about to heat up!
H=1+ (R1*sC2)/((s.C1.R1+1)*(s.C2.R2+1)) = (((s.C1.R1+1)*(s.C2.R2+1)) + (R1*sC2))/((s.C1.R1+1)*(s.C2.R2+1))
So the denominator is fine now = (s.C1.R1+1)*(s.C2.R2+1)
now the numerator : (s.C1.R1+1)*(s.C2.R2+1) + (R1*sC2) = s.C1.R1.C2.R2+s.C1.R1+s.C2.R2+1+R1*sC2
now the options are :
: s.C2.(R1+R2)+s.C1.R1.C2.R2+s.C1.R1+1
: s.R1.(C1+C2)+s.C1.R1.C2.R2+s.C2.R2+1
:s.R1.C2(1+s.R2.C1)+s.C1.R1+s.C2.R2+1
none of them can lead to a result as = X( 1+s.CxRx)(1+s.CxxRxx)
Someone who sees something I'm unable to?
Cheers