Uploaded January 2024 | Updated September 2026, 1 week ago

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When doing PCB layout and designing boards, many people ask if GND is important for differential pair signals. Here is the answer. Thank you Eric.

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Chapters:
00:00 What is this video about
01:16 P & N
02:09 Real differential pair vs. two single ended lines
07:11 Differential pair going through a transformer vs. ground
08:35 Are diff pairs routed on board different from diff pairs in cables?
11:42 Differential vs. common
15:12 What if a differential pair doesn't have any return plane - examples explained
17:28 Simulation of a single ended signal vs. return current path
21:05 Simulation differential pair signals vs. return current path
24:04 Tightly vs. loosely coupled differential pairs
28:51 Differential pairs vs. return plane far away
34:03 Example 1: Single ended signal in cable
34:56 Example 2: Single ended vs. differential signal in cable
36:22 Results: Impedance graphs
39:51 Example 3: Single ended vs. differential signal in PCB without GND plane

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