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lwew96

Pmod da3 reconstruction filter

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Posted (edited)

i have created sine wave 80khz but it is like digital signal . 

So anyone help me give some IC for   reconstruction filter of Pmod DA3.

Thank you so much!

IMG_20190408_2105331.jpg.bb543e936dc02a665f67aa756d799d6f.jpg

Edited by lwew96
i forgot picture

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Hi @lwew96,

We have not used a reconstruction filter. I did find a paper that discusses a reconstruction filter with the AD5541 here.  Hopefully one of the more experienced community members will have some input for you as well.

best regards,

Jon

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tks @jpeyron

4 hours ago, jpeyron said:

Hi @lwew96,

We have not used a reconstruction filter. I did find a paper that discusses a reconstruction filter with the AD5541 here.  Hopefully one of the more experienced community members will have some input for you as well.

best regards,

Jon

Thank you so much!

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On 6/21/2019 at 12:37 PM, xc6lx45 said:

You could try a 10 ohms series resistor, then a 150 or 180 nF parallel capacitor to ground.

i Used 3x 1k ohm series resistor and 3x 10 pF  capacitor to ground to creat 3-rd low pass filter . The result is below picture. The signal  is distorted

IMG_20190627_150901.jpg

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You are outputting a sinewave, right?  At what digital amplitude?  Both of these look consistent with quantization noise.

Dan

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10 minutes ago, D@n said:

You are outputting a sinewave, right?  At what digital amplitude?  Both of these look consistent with quantization noise.

Dan

Dan seems on to something. Are you sure you have a low-pass filter, not a high pass one? 

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is this 10 ns per division on your scope? This is unlikely to show an 80 kHz sinewave...

A picofarad capacitor isn't likely to help. The values I gave are not the only choice but they were calculated for an 80 kHz sine (resulting in a 100 kHz or 88 kHz cutoff frequency).

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