# Is this how the lowpass butterworth analog filter can be implemented?

Is this how the lowpass butterworth analog filter can be implemented?

• sure, but you might need to know the values of $L_1$, $C_2$, $L_3$, and $R_4$ to get a 3rd-order butterworth LPF at with corner frequency, $f_0$, that is specified in advance. – robert bristow-johnson Dec 28 '14 at 21:14
• Ok. Thanks, but is there a circuit to implement the 4th order analog lowpass butterworth filter? – ammar Dec 28 '14 at 21:23
• you will need 4 reactive elements to get to 4th-order. perhaps another capacitor in parallel with the load resistor might do it. – robert bristow-johnson Dec 28 '14 at 21:50