# calculating the resistors, capacitor values for pole zero low pass filter

#### dumindu89

Joined Oct 28, 2010
113
I need to calculate the resistors and capacitor values for a pole zero (low pass) filter. The cut off frequency is 70 kHz.

#### nomurphy

Joined Aug 8, 2005
567
F = 1 / 2pi*R*C, therefore R = 1 / 2pi*F*C, or C = 1 / 2pi*R*F

In the reasonable value range, one answer out of many is 22.6K and 100pF.

#### crutschow

Joined Mar 14, 2008
31,115
F = 1 / 2pi*R*C, therefore R = 1 / 2pi*F*C, or C = 1 / 2pi*R*F

In the reasonable value range, one answer out of many is 22.6K and 100pF.
That, of course, is for a single-pole filter which has the low rolloff rate of 6dB/octave.

#### dumindu89

Joined Oct 28, 2010
113
I am asking the calculations for a pole zero filter as shown in the following figure. There are two resistors instead of one. Then what would be the case in calculating the values?

#### Jony130

Joined Feb 17, 2009
5,435
All you need to do is to find the transfer function