Calculate Critical Frequency Low Pass Filter

Calculate Critical Frequency of Low Pass Filter





Calculating the critical frequency of a low pass filter is crucial in signal processing and electronics. It helps determine the filter’s performance and ensures the filter meets the required specifications.

  1. Enter the cutoff frequency (fc) in Hertz.
  2. Select the filter order.
  3. Click ‘Calculate’.

The critical frequency (fc) of a low pass Butterworth filter can be calculated using the formula:

fc = (2 * order + 1) / (2 * π * R * C)

where ‘order’ is the filter order, ‘R’ is the resistance, and ‘C’ is the capacitance.

Comparison of Critical Frequencies for Different Orders
Order fc (Hz)
1159.15
279.58
353.05
439.81
531.83
  • Always choose an appropriate filter order based on your requirements.
  • Consider the trade-off between filter order and transition bandwidth.
  • Use high-quality components to minimize component tolerances.
What is the difference between a low pass and a high pass filter?

A low pass filter allows low-frequency signals to pass while attenuating high-frequency signals. A high pass filter does the opposite.

Low pass filter circuit diagram Frequency response of a low pass filter

Learn more about filters from IEEE

Detailed explanation of filter design from UCR

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