Well... I write the first message in the forum, with a suggestion that was asked often in the old forum.
In several analog - as well as RF - circuits you need to separate various ground areas, to be connected in one point, possibly with a star configuration.
If you put two copper pours and join them with a trace, Diptrace assign both of them to the same netlist. This is not what we want.
Instead, put a zero Ohm resistor across the pours: this way, netlists remain separated, but from the electrical point of view you obtain the desired result.
How to have separated ground pours for analog and digital
How to have separated ground pours for analog and digital
"Scusate l'errore! E' che io questa convenzione dei segni non l'ho mai capita"
"Sorry for the mistake! Fact is, I still can't grab this current's sign convention"
(G.A. - assistant professor - lesson of theory of electronics)
"Sorry for the mistake! Fact is, I still can't grab this current's sign convention"
(G.A. - assistant professor - lesson of theory of electronics)
Re: How to have separated ground pours for analog and digita
I did this by creating a 'link' component that was just an 0603 with the 2 pads joined together by a track. This achieves the same as the author suggested but allows the analog and digital grounds to be 2 separate nets without needing an actual resistor.
Re: How to have separated ground pours for analog and digita
Tedward wrote:I did this by creating a 'link' component that was just an 0603 with the 2 pads joined together by a track. This achieves the same as the author suggested but allows the analog and digital grounds to be 2 separate nets without needing an actual resistor.
yeah! me too.. I also created link and same goes with yours, it allows the analog and digital grounds to be separated w/o actual resistor.
Re: How to have separated ground pours for analog and digita
Could someone please post an example of this. I'm just not understanding this from the description.
Is this done in the Component editor?
How do I connect it in the schematic?
THanks
Is this done in the Component editor?
How do I connect it in the schematic?
THanks
Re: How to have separated ground pours for analog and digita
A problem I have is the software delete nets with a single pin:
Why did DT decide to drop the ground connections? ERROR: Single pin in net: Net1, C3:1 / Net 2, C1:2
Update: Added a connector to get GND signals and tied the two grounds together with a simple trace in PCBeditor, no errors and the Gerber looks good.
Which results in this:
Notice the two pins without nets have a larger gap on the copper pour?Why did DT decide to drop the ground connections? ERROR: Single pin in net: Net1, C3:1 / Net 2, C1:2
Update: Added a connector to get GND signals and tied the two grounds together with a simple trace in PCBeditor, no errors and the Gerber looks good.
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Re: How to have separated ground pours for analog and digital
I don't recommend separate analog and digital ground if there is no necessary, there should be always sharing a totally same ground potential for optimal performance.
Only separate it when either of them have large current source/sink on certain node, then you should use "keepout" to guide the current flow back to the zero potential node.
Only separate it when either of them have large current source/sink on certain node, then you should use "keepout" to guide the current flow back to the zero potential node.