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Approximate Integrater

The low-pass filter acts as an approximate integrater at high frequencies. Assume

and integrate to obtain

The DC term is unimportant and may be dropped to obtain

We define

For a low-pass filter at high frequencies and

Thus the low-pass filter integrates at high frequencies but also attenuates the signal by 1/(RC).



Doug Gingrich
Tue Jul 13 16:55:15 EDT 1999