50 1 8. Design a four-pole Sallen-Key low-pass filter to implement an equal value fourth-order Butterworth response with a critical frequency of 2400Hz. All the resistors in the RC low-pass networks are 2.5k ohm. (a) Draw a block diagram first and show the roll-off rate (attenuation rate) (b) Draw the Op-Amp based detail circuit for this four-pole Sallen-Key low-pass filter (c) Determine the capacitance values required to produce the critical frequency of 2400Hz (d) Based on the "Values for the Butterworth response table, select values for the feedback resistors to get a Butterworth response ROLL-OFF DB/DECADE ORDER IST STAGE IND STAGE SRD STAGE ROLES F RR POLES DF RyRPOLES DF 1 Optional 1 -20 2 2 -40 1 1.00 ! 1 3 -60 2 1.00 2 0.765 1.215 0.152 -80 2 4 1848 0342 0.41 1 2 1.618 1 2 1.00 5 -100 2 0.56 2 1414 008 -120 2 1.922 50 1 8. Design a four-pole Sallen-Key low-pass filter to implement an equal value fourth-order Butterworth response with a critical frequency of 2400Hz. All the resistors in the RC low-pass networks are 2.5k ohm. (a) Draw a block diagram first and show the roll-off rate (attenuation rate) (b) Draw the Op-Amp based detail circuit for this four-pole Sallen-Key low-pass filter (c) Determine the capacitance values required to produce the critical frequency of 2400Hz (d) Based on the "Values for the Butterworth response table, select values for the feedback resistors to get a Butterworth response ROLL-OFF DB/DECADE ORDER IST STAGE IND STAGE SRD STAGE ROLES F RR POLES DF RyRPOLES DF 1 Optional 1 -20 2 2 -40 1 1.00 ! 1 3 -60 2 1.00 2 0.765 1.215 0.152 -80 2 4 1848 0342 0.41 1 2 1.618 1 2 1.00 5 -100 2 0.56 2 1414 008 -120 2 1.922