The ADAU1787 is a Sigma-Delta ADC/DAC which is assumed to be internally running at 6.144 MHz. Does the part have any internal analog anti-aliasing / reconstruction filtering? Often, a second order filter with >20dB suppression at the internal Sigma-Delta rate is incorporated - is that the case here?
What is the wideband response (up to F_nyq or Fs) of the decimation (ADCxx_FCOMP = ON vs. OFF) and interpolation filters (DAC_MORE_FILT = 0 vs. 1) at fs = 192 / 384 / 768 kHz, please? The datasheet seems to offer very limited information.
Hello AD, any response, please?
I have attached frequency response plots for the ADC (various HPF and FCOMP settings) and DAC (various FCOMP and DAC_MORE_FILT settings). The ADC 48kHz plot is Figure 10 of the ADAU1787 datasheet.
Note that these plots only go to 192kHz due to limitations of the Audio Precision. Also note for the 192kHz plot for the ADC, the analog generator is limited to 80kHz.
Thank you for the informative plots of the passband response. Do you have any way of showing the stopband response out to 6.144 MHz, please? One plot for the DAC (e.g. maximal response from fs to 6.144 MHz to a swept full-scale in-band sinusoid to fs/2) and one of the ADC (e.g. maximal in-band response to fs/2 when subjected to a swept full-scale sinusoid from fs to 6.144 MHz) would suffice, both at fs=192 kHz or higher.
Any response, please?
Unfortunately these plots are not available.