Asynchronous I2S FIFO project, an ultimate weapon to fight the jitter

[iancanada]

Originally Posted by Fridrik

Very powerfull scope indeed : wife can see that her husband is working late night on special project ;-) Nov 29 22:14.


What model&Brand?

Thanks Fridrik, not only powerfull, but also telling secret.

It's a LeCroy digital osc with 1GHz bandwidth and 8GHz sample rate.

Ian

[qusp]

Ian, is it just me, or does the inverted MCLK show more ringing than normal phase? is this ringing from your probe not being properly terminated or is this potato logic the unterminated driver you mentioned you would place?

secret? hmmm what secret?

[qusp]

but I have to say with the inverted MCK if we visualize without the ringing, which we can presume is an artifact or the termination of the probe; the wave does look cleaner. in normal MCLK the down stroke looks a bit different to the upstroke, with the inverted MCK it seems to exhibit a more similar shape on the up and down.

[Bunpei]

Originally Posted by iancanada

Based on my testing result, I think I have to include this normal/inverted MCLK feature into Si570 clock board V3.0 design. But my question is which one is better to be as the default configuration.

It would be very nice if you could show us noise floor profiles observed in frequency spectra of DAC output for sine wave input signals.
Can you observe any significant differences in the profiles?

[iancanada]

Originally Posted by Bunpei

It would be very nice if you could show us noise floor profiles observed in frequency spectra of DAC output for sine wave input signals.
Can you observe any significant differences in the profiles?

I hope I had a AP.

Ian

[AR2]

Originally Posted by iancanada

I hope I had a AP.

Ian

You see, and guys with AP will say I wish I have LeCroy, hahaha.
Does your scope has FFT feature? It might be manual process, but with good signal generator, you might be able to record and than read various Fqs.

[qusp]

I fear the problem he'll encounter is the depth of the noise floor =)

[hochopeper]

I'm still waiting for qusp to buy an AP so I can borrow it

[iancanada]

Originally Posted by hochopeper

I'm still waiting for qusp to buy an AP so I can borrow it

Me too .

Ian

[iancanada]

Originally Posted by AR2

You see, and guys with AP will say I wish I have LeCroy, hahaha.
Does your scope has FFT feature? It might be manual process, but with good signal generator, you might be able to record and than read various Fqs.

I hope LeCroy can do what AP dose, FFT is built in. But it optimized to high speed waveform and RF signals. Audio signal might be the most difficult signal to measure. Agree with qusp, it's the noise floor. But I'm just wondering if a really nice usb sound care with a really nice low jitter ADC clock and suitable isolator could become a half AP?

Ian