I am making a PCB with an Array of current DACs, which need ~15V, so I'm using a boost converter followed by an LDO.
I've (tried my best) to layout the dc/dc & LDO per best practices but I'm still unsure about how I should be routing the ground from the analog ICs back to the Power "management" ICs to avoid improper return paths.
Right now, I've got a Ground Plane shared by all the DACs that is separated from the boost converter except through a fill that routes thru the LDO, I tried to highlight my ground plane in the pic.
Is this correct? following the thinking that I want to have the ground return from the DACs go to the LDO instead of to the , accounting for my poor layout techniques
Does it even matter that much??? Is it preferable to just mash the Power/Analog Grounds together into one big ground plane.
Or am I actually screwing my design? I'm kind of worried i shouldn't have such a long path from the Li-ion (-) terminal to the Analog circuits ground like i have now.
Edit: Here is the annotated board.
Ground plane: Purple 7.4V from battery to VIN of Boost Converter: Light Blue +15V Vout from Boost Converter to LDO VIN: Dark Blue +12V Regd output from LDO to Every DAC: Red