Other Parts Discussed in Thread: PCM1690, PCM4202
Hello Audio Folks, a customer is using our PCM4202 ADC and PCM1690 DAC. Their end customer finds that our solution has a much bigger delay in comparing with Cirrus Logic CS4272.
The totaly delay of PCM4202+PCM1690 is 1.5ms. Sampling rate is 48KHz. CS4272 is a codec. The ADC+DAC delay is 0.5ms. This means our solution is 1ms longer than CS.
Checking our data sheet, PCM4202 group delay is 37/fs which is 0.77ms for 48KHz sampling.
For PCM1690, there is just one delay figure. It is 28/fs = 0.58ms for 48KHz sampling. So total delay will be 1.35ms. It is closed to customer measurement.
For CS4272, ADC portion delay is 12/fs. For DAC portion, even for fast roll off filter, delay is 12/fs. So, the total delay is 24/fs = 0.5ms for 48KHz sampling.
One question is that for PCM1690, any difference on the group delay for fast and slow roll off filter? The next question is any possibility to improve the delay.
Regards,
Kes
