PCM5102, 2VRMS ground centered direct output with two digital filters

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Hello Folks,

I'm the Audio Systems engineer that defined this part. I haven't had the opportunity to go through all 8 pages of this thread quite yet. (I'm hoping there isn't too much flaming... this part is my baby!)

If any of you have any questions on how to use the part, or configure it, or any other system level questions I will my best to stop by this thread from time to time. However, the main portal for tech support on these parts is over at TI's e2e forum (TI E2E Community)

Sorry Mod, I'm not trying to steal traffic from this place, just trying to show people where they can get more data and help with these parts. -- Keep up the good work! :)

Many thanks,

Dafydd Roche
 
Hello Folks,

I'm the Audio Systems engineer that defined this part. I haven't had the opportunity to go through all 8 pages of this thread quite yet. (I'm hoping there isn't too much flaming... this part is my baby!)

If any of you have any questions on how to use the part, or configure it, or any other system level questions I will my best to stop by this thread from time to time. However, the main portal for tech support on these parts is over at TI's e2e forum (TI E2E Community)

Many thanks,

Dafydd Roche

Hi, Dafydd,

Because of your audio DAC product definition role, I would like to ask if you have any information you might share about whether other T.I. audio DACs (such as in the PCM179x series) will incorporate both minimum phase and linear phase digital interpolation filter impulse/phase responses, such as in your PCM5102?

In addition, may I suggest that it would be highly desireable for the DAC's embedded digital interpolation filter to support a sharply bandimited (non half-band) implementation. Meaning, where the filter frequency response is fully in to the stop-band by the Nyquist frequency (22.05KHz for CD), yet is flat to within a few tenths of a decibel at 20.0KHz. The digital audio industry generically refers to such a filter response as, 'apodizing'.

Thank you.
 
Do you run your PCM5102 from the same 3.3V power supply for both digital and analog? Started designing a sound interface for the Raspberry Pi based on the chip. The idea is to generate a clean 3.3V analog supply from the 5V line. From this thread I guess, I should go up to 3.5-3.6V. Any comments on this?

I didn't try this specific dac in 3.6V modus, but I can't imagine the difference is that large. I do have experience with direct I2S audio from the Raspberry Pi, and it's not easy to get it to a acceptable level.

For you, it's much more important to keep the noise from the Pi away from the DAC chip.

So it's wise to separate the supply of the Pi and the DAC. Don't take a 5V from the Pi and regulate it down, but take a separate 5V source to regulate down. Make sure the 5V for the Pi is also of high quality, this helps to get the I2S signal clean.

The I2S output header of the Pi is directly connected to the Proc, impedance mismatch problems can cause a lot of trouble.

Clock quality is very low, give the DAC it's dedicated XO.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.