connect ADC & DAC Ground?

[neops]

hello

I have an ADC circuit board that has external analogue power (15+,0,15-)requirements and digital power too (5v)

I have it working from two seperate toroidal and regular PCBs.

i just noticed on the pdf that there is a digital ground symbol and an analogue ground symbol

at the moment I do not have them joined from my wiring. maybe this happens in the circuit as there is a picture that shows them joined. maybe this is optional? should i do this?

I have highlighted the symbol on the picture attached in a green oval.

thank you for help

 

[Monte McGuire]

They have to be connected somewhere, or else the digital pins ground could be very far from the analog pins ground, and you'll probably violate some voltage requirement of the chip. Definitely connect them together at one place, probably where the analog and digital supples each connect to the PCB.

 

[neops]

hi thanks for your reply.

I had a slight brain wave to try a continuity test (lol ; ) and the grounds are already joined on the PCB.

So although the symbols for these grounds are different they are joined.

so you were right.

thank you.