I'm not sure what your point is, but the question was, "how do I
connect together the digital ground and the analog ground on my PC
board?" and the answer is that there is no need to connect them on
the PC board. Saying that something is unnecessary is not the same
thing as saying that it will cause a problem.
The issue is not whether a module can propagate noise through the
power supply connections to other modules. The issue is whether the
digital circuitry on a module can propagate noise to the analogue
circuitry on the same module. One way to try to prevent that is to
separate the analogue and digital grounds on the board, and connect
them near the supply where the ground impedance is lowest.
You are saying that it is ideal to have the grounds connect at only
one point, and I agree, but you are also saying that you can have
them connected both at the board and at the 950, which would be
connecting them at two points. Whether or not that causes a problem
depends on the module.
On 10/30/06, Richard Brewster put forth:
>There are two questions here. One is whether analog and digital grounds
>can be connected together on a PC board connected to a MOTM-950. The
>answer to that is, Yes, because the two are connected on the MOTM-950
>itself anyway.
>
>It's a different question whether a module can propagate noise through
>the power supply connections into other modules. I am sure that is
>possible. If noise could get through simply due to the analog and
>digital grounds connected, then the MOTM-950 would be subject to this
>problem for ∗any∗ set of modules supplied by it. Analog and digital
>grounds have to connect somewhere. At one point is ideal. The 950
>provides that point.