Quote:
I just stumbled on this thread. I'm not sure you fully understand the
concept of a starred ground.
It will not speed things up. It is intended to isolate ground currents.
In digital, you need to keep grounds clumped together, not isolate
them.
Dwight
The star is part of what I advocate for wire-wrapping (or any board lacking a true ground plane), for the power and ground connections, with the power source and largest capacitors in the center. It's really more like a spider web
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spiderweb.jpg [ 43.58 KiB | Viewed 1024 times ]
with power and ground connections going around the center as well, from one IC to the next. I still advocate the bypassing as each IC as well unless you have both a ground plane and a power plane.
As Dwight says, there are still places like A/D converters which may need their own isolated power and ground region to keep digital or SMPS (switch-mode power supply) noise out of them, and I also give SMPSs their own plane area to keep the switching noise out of analog circuits. The plane sections are joined only at one place, with bypassing there, and the signal traces are brought through as close as possible to that point, not crossing the chainsaw line at just any ol' place. Putting a trace across a cut in a ground plane is a good way to get an antenna, and is in fact one way antennas are done in hand-held wireless devices. This is why ground pours do not qualify as a true ground plane.
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