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Cut off Freq for Class D amp

It depends on whether the phase shift of the output with respect to the input is important. A 1KHz single pole filter would give approximately

22 deg of lag @ 400 Hz.
Reply to
Jon
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I am designing a switching class D amplifier who's H-Bridge will be switching around 138Khz. The fundamental I need to recover at the load is

400Hz. Does it matter too much where i should make the filter cut off at? I know higher cut off freq, smaller the components. I am thinking around 1Khz?

Thanks in advance

Reply to
toyo22r

And the amount of ripple, which should not be ignored.

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Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
Reply to
Tim Wescott

the

approximately

Thanks... I have a couple of designs i will breadboard and evaluate.

Reply to
toyo22r

If the 400Hz is moving about a lot then a minor point could be raised that the filter may best be designed as something having a clean impulse response and hence won't suffer too much from 'ringing' artefacts on the output waveform. You've lots of meat to eat into, so something like a Bessel filter starting to roll off from say 20kHz may be worthwhile. regards john

Reply to
john jardine

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