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Altera_Forum's avatar
Altera_Forum
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15 years ago

how to design a low pass digital filter with smallest delay

Hello, All I want to design a digital filter with the cutoff frequency 20Hz. The sampling frequency of my acquiring system is very high, up to 8192 Hz. The important requirement is the de...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

2 kHz cut-off is fine, of course. The lowest cut-off, I could achieve with standard design methods was 45 Hz for a rectangular window and 75 Hz with a reasonable window function.

A 50 Hz notch filter, that can be also realized with 81 taps (although it actually uses 2 taps only) achieved about 25 Hz 3 dB cut-off for the first notch, but it's no low-pass.