DS16EV5110A: HDMI signal issue

Poh Kok Keng

Part Number: DS16EV5110A
Other Parts Discussed in Thread: DS16EV5110

Dear Sir/Madam

We’re using DS16EV5110ASQ/NOPB in our project, DS16EV5110ASQ/NOPB and was facing some error. Our HDMI output (the monitor) cannot get signal and could not display anything. We measure the signal and it show below. Every 1160ms there’s a 40ms break. Do you have any idea what could cause it.

Note: Good signal should be continuous with no break.

Best Regards,
kpk

over 2 years ago

0 Nasser Mohammadi over 2 years ago

TI__Guru* 93100 points

Hi KPK,

1). 1160ms is close to 0.86Hz. I am not aware of clock within the part that can generate this. Does this occur on every part?

2). Do you observe the same waveform if there is no input or no cable attached to the input?

Regards ,,Nasser

0 Wang Teck Ann over 2 years ago

Prodigy 20 points

Hi Nasser,

1. No. we have build 2 PCBA using this IC, the first PCBA we can get the display on the monitor, by using HDMI cable shorter then 1m in the input, but the monitor was not able to get the signal using HDMI cable longer then 1m. In the 2nd PCBA (same HW with different placement), the monitor was not able to get the signal even using HDMI cable shorter then 1m.

2. No. There will be no waveform if there is no input or no cable attach to the input.

For your info. the HDMI input was connected to FPGA, the FPGA forward the output to DS16EV5110ASQ and to the HDMI connector. It seems like the length of the input HDMI cable will cause the error display in monitor.

0 Nasser Mohammadi over 2 years ago in reply to Wang Teck Ann

TI__Guru* 93100 points

Hi KPK,

Is it possible there could be some grounding issue? Device cannot generate thislow frequency signalon its own.

Please also send us your schematic as well.

Please below note DS16EV5110A EVM schematic. Please compare your schematic with this file:

https://www.ti.com/lit/ug/snlu015/snlu015.pdf?ts=1634692630531&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FDS16EV51-AEVKH

Regards ,, Nasser

0 Wang Teck Ann over 2 years ago in reply to Nasser Mohammadi

Prodigy 20 points

Hi Nasser,

What possible grounding issue that you mention above?

I have tried using a HDMI to VGA converter and it did display successfully but intermittent (less than a second display and off and display and off), and there's some color dots on the display (see attach).

Can you advise what is the possible cause of this?

Thanks.

0 Nasser Mohammadi over 2 years ago in reply to Wang Teck Ann

TI__Guru* 93100 points

Hi KPK,

1). Please refer to the report below and you can observe we have tested DS16EV5110 with a much longer cable length. This means there is something different with cable/shielding that you are using versus what we have.

2). Additionally we are not using any clock at this low frequency - close to 1Hz - within the part. This low frequency does not seem to show up until you attach the cable. I don't think the video generator can be sending this low frequency signal so the only thing that came to mind was perhaps cable GND may not be fully GND. I could be wrong though.

3). Also can you please try another video source - do you see a similar behavior?

4). Dots within the image show some signal integrity issue. Please note table 4 of the attached document. Can you please sweep EQ gain settings - while you have dots within this image - to see if you can fine tune the settings to get rid of these dots?

Regards ,, Nasser

https://www.ti.com/lit/an/snla095b/snla095b.pdf?ts=1634850886299&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FDS16EV5110%253FkeyMatch%253DDS16EV5110%2526tisearch%253Dsearch-everything%2526usecase%253DGPN

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DS16EV5110A: HDMI signal issue