keron Posted June 5, 2014 Report Share Posted June 5, 2014 I am here with this DAC design with PCM1704 and the standard circuit provided by BB. As you can see in their datasheet.(Page 9)http://www.ti.com/lit/ds/symlink/pcm1704.pdf But I do not think they did justice with the DAC chip by throwing a simple post DAC filter in the Typical application circuit >:(. But I understand it is for 8x Oversampling topology and should work just fine. My case is a bit different by going for NOS(non oversampling ) in fact more complicated since I do want to play back CD material through the DAC which samples at 44.1Khz. The standard filter recommendation is a Bessel filter of 3rd order or higher for oversampling topology, but for NOS ............. I am not sure I am not clear about which filter topology to use too. But my understanding is the phase linearity is as important as the cut off Frequency. I have few CD DAC circuits that start filtering at 40Khz.I know the the first ALias will appear at 22.5KHZ but I do not want to start my -3dB slop much before it. Do not want introduce Phase non linearity with a filter which will possibly ruin the NOS effect.Can someone help me? Quote Link to comment Share on other sites More sharing options...
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