I want to use the dual DAC on the ESP32 and am having some trouble understanding the datasheet.
I've found that noise from my input power supply shows up on the analog output.
I would like to install a choke and filter to the analog domain power pins to help clean them up from switching noise produced by my supply and the digital domain operation of the ESP32.
What pins should I treat as "analog VDD" versus "digital VDD"? I see there's only one ground so I'll share those, but I may as well get the input voltage cleaner.
I see VDDA which seems to be analog domain, but I also see VDDA3P3 which in the PICO datasheet is called the "Power Supply Amplifier" and is indicated to be in the analog domain, with the main ESP32 datasheet describing it as "Analog power supply" (same text as VDDA).
To make it a little more confusing, the PICO datasheet describes pin 46 as "VDDA - Digital power supply for PLL" while the main ESP32 datasheet describes it as "VDDA - Analog power supply".
And then in the hardware design guidelines, it seems to have a choke going to VDD3P3 (pins 3/4) but *not* to VDDA (pin 1).
If I want to install a choke and some extra filter capacitors to the pins that will power the DAC, do I connect the filtered side to VDD3P3 only, VDDA only, or both? And what's up with pin 46?