Hi, Mr. Eugenio,
Indeed, I sent only a small portion of the schematics (only the portion tha trelates to the ADC8832)
I also kept the connection between AGND and the DGND out of the schematics, but they are shorted through ferrite beads and an ADC.
My question relates to the DAC chip:
1. What is the coupling the chip between PD, AGNDF/S and GND? Are they electrically isolated? Are they shorted? Is there resistance/capacitance between them? Can you send me the equivalent circuit between the 4 nodes (PD, AGNDF/S and GND)?
2. I seem to have made a mistake and connect P3V3_D (3.3V, digital voltage) to the VDD input pin - instead of analog voltage. What is the coupling between VDD, and the other 4 ground nodes (PD, AGNDF/S and GND)?
Please note that the input voltages into the VCA (that is controlled by the output voltage of this DAC) is in the range of 50uV. Noisy ground and supply of the VCA damage the input signal. I am afraid that the DAC causes leakage from the digital domain to the analog domain.
Thanks,
Avishai