longstar
Member level 2
If we get the parameter of the LPF,such as order,cutoff frequency,attenuation,gain,and so on.So how can we design the LPF under the condition?
For example,I want to get a 4th order Butterworth LPF,the cutoff frequency(3dB Bandwidth) is 8MHz,the attenuation of stopband is 40dB at 27MHz,maybe the 1dB bandwidth is 6.5MHz.Surely, the architechture of the filter is selected.The first and the second filter are also the RC 1th LPF,the later filter is sallen-key LPF.
Based on the above massage, how can we get the R and C value?Could you can give me some idea?Thank you very much.
For example,I want to get a 4th order Butterworth LPF,the cutoff frequency(3dB Bandwidth) is 8MHz,the attenuation of stopband is 40dB at 27MHz,maybe the 1dB bandwidth is 6.5MHz.Surely, the architechture of the filter is selected.The first and the second filter are also the RC 1th LPF,the later filter is sallen-key LPF.
Based on the above massage, how can we get the R and C value?Could you can give me some idea?Thank you very much.