Does separating DGND and AGND with two different layers for each make any sense?

Question

In my last question I found out that having two different layers for Ground and Analog Ground may induce capacitive coupling. Now I want to ask more generally if the idea I had is worse than connecting DGND and AGND on the same plane. May PCB stack-up is currently as follows:

Signal, DGND, AGND, Signal

My PCB looks like this:

So there is an ESP32-S3 (bottom right), MAX6675 temperature sensor (top right), camera interface (SCCB) working at 20 MHz (top mid), Li-po charging circuitry (top left), Li-po protection circuitry (top left), 3.3 V power supply (left mid), 1.5 V and 2.8 V power supplies (left of cam connector) and an ADC (ADS1110) above the battery connector.

To the AGND plane is only connected the AGND Pin of the 3.3 V power supply and the AGND pin of the camera.

If it is a bad idea, how can I make it better?

Answer 1

My PCB Stackup is currently as follows:

Signal, DGND, AGND, Signal

Put DGND and AGND on the same layer to avoid the problem that you mentioned (capacitive coupling) and, to keep both GNDs close below the components they are acting as a GND-plane for.

You just need to figure out how and where you connect the AGND and DGND planes (hint a single point connection at the junction of some type of analogue to digital conversion I.C. is normally recommended).