Hello York,
The latency in ADC's and DAC's are dominated by the decimation and interpolation filters inside the devices. this number can be found by looking for "latency" or "group delay" in the datasheets.
One sample of delay at 48kHz = 20.8uS
The specification you provided suggests that you need ADC + DAC Latency < 20uS.
If you run at 192kHz, you'd have <4 samples of time to process in to out.
If you run at 384kHz, you'd have 8 samples. However, you may be able to bypass the interpolation filter if your content is running at 384kHz.
We may be able to support such high sampling rates with some of our portable codecs. Sadly, my knowledge is more on the higher performance converter side of the house. I will need to get a colleague to comment further.
However, I will say, <20uS is a VERY difficult target.
Thanks again
Dafydd Roche - Audio Systems Engineer@TI.
