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content="Formulas for a 1st order Butterworth active lowpass filter.">

<title>HwB: Active Filter: Butterworth 6dB Lowpass</title>
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<h1>Active Filter: Butterworth<br>
(1st order, 6 dB/octave, Lowpass)</h1>

<p><img src="images/misc_ActiveFilter1L.GIF"
alt="1st order Butterworth Lowpass" width="191" height="111"></p>

<p>R=4.7k-10 kOhm<br>
C=1.000/(2*pi*Fc*R)</p>

<p><font size="2"><i>Units: R [Ohm], C [F], Fc [Hz]</i></font></p>

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    <font size="2">Contributor: </font><a
    href="mailto:qtech@mailhost.net"><font size="2">Joakim Ögren</font></a>
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    <font size="2">Source:&nbsp;?</font>
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