Video interference

cxq742536574

Video interference [Copy link]

The two modules have shielding ground and power ground. When both grounds are connected, the video signal is interfered. When the power ground is disconnected and only the shielding ground is retained, it is normal. Why is this?

cxq742536574

I hope you can give me some pointers.

hd_cqm

Generally, the signal is grounded, why is the power ground connected?

Jacktang

Disconnect the power ground and keep only the shield ground normally.

Obviously there is a power problem

吾妻思萌

Oscilloscope measures the ground-power-ground crosstalk ~ Does the PCB design separate the power ground and the digital ground?

cxq742536574

Azuma Simeng published on 2023-9-21 08:28 Oscilloscope measures ground-to-power-ground crosstalk ~ Does the PCB design separate the power ground and digital ground?

It is power supply interference, the ground plane is shared

吾妻思萌

Azuma Simeng published on 2023-9-21 08:28 The oscilloscope measures the ground-power-ground crosstalk~Does the PCB design separate the power ground and the digital ground?

It is power supply interference, and the grounds all share the ground plane

If there is interference, you can try not to share the ground.

led2015

Interference in the video signal is most likely caused by an incorrect connection of the ground return.

chunyang

There is insufficient information to make a judgement. Specific information on the connection points and even some peripheral circuits and local PCB diagrams should be provided for better analysis.

火辣西米秀

Shield ground and power ground, when both grounds are connected, the video signal is interfered

Grounding is a technical job

How is the shielding ground connected?