I2S isolation for DAC

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I have considered the transformer solution too, but wouldnt that result in a phasshift/time delay between the MCLK and the other i2s signals? or does that not matter for an application like this?

A phase shift between MCLK and the I2S signals doesn't matter.

A transformer for MCK? Never heard of this idea. What would happen to the square wave? Would it not be worse than jitter?

If a suitable wideband trnsformer is used, the jitter can be very low. Much lower than with digital isolators.
 
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Joined 2009
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I did an isolator chip in my I2S signal with an IL715 chip.
It is a 4-channel supporting 100 MHz so 45/49 should pass through o.k.

I use it for I2S only so never tested it at higher than 12 MHz BCK so you have to test yourself how signal quality will be through the chip.

I use a Beaglebone Black with add-on board for dual clock 22/24 MHz and the IL715.
My measurements show a nice cleanup of PC noise once passed the isolator.

Hardware:

1k0.jpg


44.1 LRCLK before isolator:

1k0.jpg


After the isolator:

1k0.jpg


44.1 BCK before isolator:

1k0.jpg


After:

1k0.jpg


The power supply used for both sides of the chip are AMS1117 regulators for 3.3V out.
 
Sorry to resurrect this thread, but I'm wondering what exactly is necessary to use the ethernet-style transfermers to filter the signals. It looks like it is as straightforward as installing the transformers inline, but that seems too simple to me.

I am trying to clean up an i2s signal from a particularly noisy wifi/bluetooth/usb streaming board (Arylic) that has some ugly switching noise overlayed on everything.