ADC group delay on 1701/1702

Hello Christian,

I measured the appoximate group delay values on the bench today using an EVAL-ADAU1701MINIZ.

The DSP core itself has a very small group delay of one or two samples.

The ADCs have a group delay of about 25 samples, or 0.5 ms @ 48 kHz.

The DACs have a group delay of about 25 samples, or 0.5 ms @ 48 kHz.

The complete ADC-DSP-DAC path has a group delay of ~50 samples, or 1 ms @ 48 kHz.

Best Regards,

Brett

The actual group delay of the ADC filters is about 0.48 ms and the group delay of the DACs is about 0.4 ms. The extra delay Brett measured on the bench is due to some small delay through the serial ports. This delay is constant across frequency.

The group delay mentioned above is for the core with no processing. Of course, the delay may increase depending on the type of processing done. Some blocks, such as filters and delays (obviously), have an inherant delay in the signal path.