Why this capacitor?

[Roky]

Hi everyone
Why this capacitor on network schematic in the base board Voipac project ?


thank you in advance

[robertferanec]

That is unfortunate way to draw schematic - the grounds are not the same net, the grounds should use different symbols. Very well spotted.

Here is screenshot how it looks when you make "Name" properties visible on the Ground symbols - you can see one is connected to GND net and the other is actually CASE_GND:

[Roky]

Ok, thank you Robert,

so I guess CASE_GND is the ground in the mounting holes
and the capacitor helps only to discarge fast "common mode" signals
like testing ESD signals or some kind of "bad" singnals coming from the network

am I wrong??

thank you again for you fast reply
Rocco

[robertferanec]

I checked, they have CASE_GND connected only locally under the Ethernet.

But, you are right,, if you are using CASE_GND you may want to connect there also other things like mounting holes or shield of other connectors. And yes it helps with ESD.

[Roky]

Thank you very much.