Split or Continuous Ground Planes

R_K

In one of our design we have split ground planes known as “CHASIS GND” and “DIGITAL GND” connected with a 0 Ohm resistor.

Is it advisable to combine both these ground planes for better EMC?

PS:

1] The “CHASIS GND” is connected only to casing of D-SUB 15/9 connectors and it was isolated from “DIGITAL GND” to avoid any interference that might come from both these connector casing directly into digital section of the board.

2] Some of the signal traces on adjacent layer are crossing over the etched copper section which separates both these ground planes.

Thanks in advance.

over 7 years ago

0 Elias Villegas M. over 7 years ago

TI__Guru* 76130 points

Hello,

I would recommend to keep them isolated, do not cross split planes.

Regards

0 R_K over 7 years ago in reply to Elias Villegas M.

Intellectual 385 points

Thank you Elias Villegas M. for the above suggestion.

As seen in above image our previous Engineer had not connected the casing of "USB - TYPE A" to "CHASIS GND" but he had connected it directly to "DIGITAL GND".

To improve our layout in terms of EMC, Should we connect the casing of "USB - TYPE A" to "CHASIS GND" as seen in below image?

0 Elias Villegas M. over 7 years ago in reply to R_K

TI__Guru* 76130 points

Hello,
Yes, the connector chassis should be connected to "CHASIS GND"
Regards

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Split or Continuous Ground Planes