Post Go back to editing

(ADV7390)Noise output from the device.


Hi !

I have some question about ADV7390.

Some kind of noise is output from ADV7390.

I am using ADV7180-ADV7391 Eval-board and using "CVBS auto detect" script.

=> I attached the script file.

And I zoomed the waveform.

The BT.656 data is output from ADV7180 and at the EAV and SAV point , ADV7390 output some kind of noise.

Also I setup the ADV7180's resister, 0x0C to "Force free run mode" and "Output 100% black".

Why does this noise output from ADV7390?

And also to prevent outputting this noise what should I do?

Is it possible to erase this noise by setting resister?

I want to know this because our customer have this issue.

I will attach customers waveform.

Also at the display, blue line is in the display.

Our customer think this happens because of the ADV7390's noise output.

I will check about this(display image) connecting ADV7180-ADV7390Eval board to other Eval board

and moving the image area to check this will happen or not .

But I am out this week so it will be next week.

If you can tell me why this will happen and how to solve this problem, it will help us and our customer very much.

Best regards.

Kawa

attachment.zip
Parents
  • Yes, it would be unlikely that noise is generated the ADV7390.  To me that looks like something generated by something else in the system that is locked to the horizontal sync.  If it was an old CRT monitor, I'd say it was the horizontal retrace circuit causing this spike.  I'd check everything that is locked to the horizontal sync.

Reply
  • Yes, it would be unlikely that noise is generated the ADV7390.  To me that looks like something generated by something else in the system that is locked to the horizontal sync.  If it was an old CRT monitor, I'd say it was the horizontal retrace circuit causing this spike.  I'd check everything that is locked to the horizontal sync.

Children
No Data