The following table lists values of components for common corner frequencies in Butterworth filters. If designing
your own filter, software from Burr-Brown provides the component values to create the desired filter. Note that
the design math is beyond the scope of this manual.
3-Pole Butterworth Filter Components
3dB (Hz) RCnA RCnB RCnC RCnD RCnE RCnF RCnG RCnH
0.05 3.16 MΩ 1 µF none 3.16 MΩ 1 µF 3.16 MΩ none 1 µF
0.10 1.58 MΩ 1 µF none 1.58 MΩ 1 µF 1.58 MΩ none 1 µF
0.20 787 kΩ 1 µF none 787 kΩ 1 µF 787 kΩ none 1 µF
0.50 3.16 MΩ 0.1 µF none 3.16 MΩ 0.1 µF 3.16 MΩ none 0.1 µF
1 1.58 MΩ 0.1 µF none 1.58 MΩ 0.1 µF 1.58 MΩ none 0.1 µF
2 787 kΩ 0.1 µF none 787 k Ω 0.1 µF 787 kΩ none 0.1 µF
5* 3.16 MΩ 0.01 µF none 3.16 MΩ 0.01 µF 3.16 MΩ none 0.01 µF
10* 1.58 MΩ 0.01 µF none 1.58 MΩ 0.01 µF 1.58 MΩ none 0.01 µF
20 787 kΩ 0.01 µF none 787 kΩ 0.01 µF 787 kΩ none 0.01 µF
50 3.16 MΩ 0.001µF none 3.16 MΩ none 3.16 MΩ none none
100* 1.58 MΩ 0.001µF none 1.58 MΩ none 1.58 MΩ none none
200 787 kΩ 0.001µF none 787 kΩ none 787 kΩ none none
500* 316 kΩ 0.001µF none 316 kΩ none 316 kΩ none none
1000* 158 kΩ 0.001µF none 158 kΩ none 158 kΩ none none
2000 78.7 kΩ 0.001µF none 78.7 kΩ none 78.7 kΩ none none
5000 31.6 kΩ 0.001µF none 31.6 kΩ none 31.6 kΩ none none
10000 15.8 kΩ 0.001µF none 15.8 kΩ none 15.8 kΩ none none
*These pre-configured Butterworth frequency modules are available from the manufacturer.
You have the option to configure the filter sections as band-pass filters rather than low-pass filters. The
component selection program provides band-pass component values. The program also computes and
displays phase and gain characteristics of the filter sections as a function of frequency.
Software Setup
Reference Notes:
o DaqView users - Refer to chapter 3, DBK Setup in DaqView.
o LogView users - Refer to chapter 4, DBK Setup in LogView.
DBK Option Cards and Modules 918894 DBK18, pg. 5