Linked Questions

13
votes
3answers
6k views

How to Connect USB/Ethernet Shields to Chassis or Digital Grounds

I have a PCB with a few USB and RJ-45 Ethernet connectors on one side. I'm quite confused as to how exactly I'm supposed to be hooking up the SHIELD pins on them though. This is for a host device ...
11
votes
3answers
17k views

Physically, how does connecting a PCB to chassis ground reduce noise?

I realize this may seem to duplicate Should chassis ground be attached to digital ground? but the answers in that thread don't explain why one should connect the chassis to PCB ground, aside from ...
11
votes
1answer
4k views

PCB 'Emi proof' design

Currently I'm designing a GPS basestation which will have a radiomodem (broadcasting at 407-480MHz), a ARM7 microcontroller running at 60MHz and a FTDI USB chip. The FTDI USB chip even runs at 480MHz ...
3
votes
2answers
4k views

Ethernet phy connection: grounding between chassis, connector and IO

The phy chip I'm using has a evaluation board which grounds the chassis, connector and signal gnd points in the following way: However, I don't really understand why the MCTx connections are ...
5
votes
1answer
4k views

AC->DC supply, how to deal with chassis ground being connected to digital ground?

I have an external triple-output AC-DC supply with the following output pinout: On the power supply, "ground" (pin 2) is internally connected to the ground wire of the mains plug. I'll refer to it as ...
4
votes
1answer
904 views

Best practice design ground and shielding

Case: I design a pcb with a microprocessor and a adc (I'll leave out the details). Is this correct: The digital ground and the analog ground should be connected, but by a small passage. Next ...
4
votes
1answer
551 views

ESD Protection on Un-grounded Chasis

I am designing a product solution which needs a 240V AC to 12V DC. I am getting that done with one of those standard laptop chargers from a reliable OEM(with necessary certifications) which looks like ...
1
vote
1answer
705 views

Should Shielding GND be isolated from circuit GND?

In my system, I have 3 Grounds: DGND, AGND and Shielding GND, What steps should I take to isolate shielding ground from the other grounds that exist? Should I connect them with ferrites or use some ...
1
vote
1answer
636 views

Metal connector case connection when using a plastic housing

I'm designing a board with 2 SFP connectors and I am not sure what I should connect the cage pins to. The manufacturer recommends connecting the case pins to chassis ground but my product is in a ...
1
vote
1answer
576 views

Decision on connecting Earth Ground to one of Two GND pins

I'm planning to design a board that is suitable for industry so EMC is so important. I have decided to use two separate power supplies(+5v and +24v) to Isolate the board from outside world. ...
3
votes
1answer
377 views

How to connect GND between both sides of a signal transformer

I am doing a test board to learn more about ethernet, differential pairs, etc. I understand that the transformer will isolate my board from the world. But I wonder how to design the termination ...
0
votes
0answers
379 views

Connecting Protective Earth (PE) to DC ground

This question has a bit of application background so please bear with me: I'm working on a LED lighting system. The controller (MCU, led drivers and led supply) will be powered by a single DC ...
0
votes
0answers
358 views

W5500 Ethernet Chip Layout Advice/Help

I am working on a project that includes the W5500 circuit, this is the first time i had the opportunity to layout Ethernet Interface circuits. Schematic: Whole board and W5500 Module Layout ...
1
vote
1answer
124 views

How to shield a battery powered instrumentation with USB interface?

I would like to ask for advice on shielding the following setup. I have a measurement target sitting inside a Faraday cage, connected through a shielded cable to a measurement circuit. The cable ...
0
votes
0answers
147 views

Connecting the Chassis Ground and Signal Ground in my PCB

I have been reading alot of questions on this site to clear my understanding on Chassis, Signal Ground, ...