Hi,
The low power audio codec, ADAU1372/1772, ADAU1777 and ADAU1787.
To use these devices for the noise cancelling system, I would like to understand correctly about following Group delay values.
ADC in - ASRC - Serial out
Serial in -> ASRC -> DAC out
In the data sheets, there are several plots that show "Group delay vs Frequency", for example, as below.
ADAU1777
Figure 32. Group Delay vs. Frequency, fS = 786 kHz, Signal Path = AIN0 to ASRC to ADC_SDATA0
Figure 44. Group Delay vs. Frequency, fS = 786 kHz, Signal Path = DAC_SDATA to ASRC to LOUTLx
Regarding them, please let me ask.
Q1. Serial port sampling rate, the condition for the Group Delay vs. Frequency plots
Q2. How does the Group delay changes, depending on the Serial port sampling rate ? Are there any calculating formulas?
Q3. Do the ADAU1372/ADAU1772, ADAU1777, ADAU1787 have similar Group delay values and characteristic?
The other devices, AD1896 and ADAU145x/146x have the calculating formula for the ASRS's group delay.
It shows that the delay value changes depending on the input/output sampling rate.
But it looks that the low power codec’s group delay is much shorter than it.
