How to implement star ground connection for GND and AGND with copper areas in PCB?

[vivek20055]

Hi,


I need to use star point grounding connection for AGND and GND in PADS software??


I have seperate copper areas for GND and AGND in my 4 layer pcb design.


How can I implement star point grounding connection for AGND and GND???


I am attaching the image for AGND and GND of my design???



Regards
Vivek

 

[FvM]

I'm unable to recognize what's intended as GND or AGND in the picture.

To support star connected nets in autoroute, power plane connection and design rule check, you need to implement a kind of net connector component, if it's not already provided with your layout tool.

In the schematic view it's a jumper connecting two logical nets. In layout, it'a a piece of "non-electrical" copper shorting two SMD pads or vias. The non-electrical copper most be added to regular artwork in postprocess. You also need to correct netlist exported to test tools, e.g. IPC356.

 

[vivek20055]

Hi,

Thanks for your reply

I really do not understand the option that you told me in layout.
can you please eloborate and tell me whichnon electrical option in layout that connects both analog ground and digital GND


regards
Vivek

 

[FvM]

I really do not understand the option that you told me in layout.

I don't know the aviable features with Pads in this regard, thus I can't tell you "how to" exactly.

Essentially, I suggest to find a way to place copper in your layout, preferably as part of a dedicated net connector PCB part, that's not considered as short in design rule check.

 

[sivamani]

Why do u need star ground When you have separate gnd net for Digital and Analog.Star ground concepts comes when you want to isolate analog and digital gnd section using single net.

 

[FvM]

Why do u need star ground When you have separate gnd net for Digital and Analog.

GND and AGND need to be connected somewhere. You often want to connect the nets in PCB copper rather than by an external component.

 

[Mattylad]

CADSTAR has a star point in it that would allow you to do this, however the old way is to make a little component that has 2 pads, is about the same width as the track and place some copper between the pads.
Then accept the errors given.