AD8195 - max. cable length for ddc lines

Hi,

 Did you refer this thread?

   https://ez.analog.com/video/f/q-a/12022/output-hdmi-distance-max-with-ad8195

Believe that this would be helpful.

Thanks,

Poornima

Hello,

thanks for the reply. I read this thread already.

But what i can not read there is: was this test done only with hdmi signals or with hdmi and ddc.

Maybe another discription will help to point out my problem.

I have a hdmi source which only transmit hdmi signals if it could read out the edid-eeprom first.
If the read/write of the edid-eeprom fails because of the 20m cable (and because the AD8195 dont boost these signals) my hdmi source will never send any hdmi signals and therefor my system wont work. But i am not sure if DDC over 20m hdmi cable is really a problem or if i am only to fearful.

So i have two Options:
1) assume that analog done the tests with ddc signals and i can use figure 34 from datasheet as my reference
2) use a extra ddc bus expander (like max3816) as backup to be sure it will work

Best Regards Eric

Hi,

DDC: Display Data Channel, one of the channels in an HDMI connection. DDC allows devices to assess each others’ capabilities and adjust themselves accordingly. For example, a DVD player can discover the maximum resolution of the monitor it is connected to by reading the monitor’s EDID chip and optimize its signal output to match that monitor’s display capabilities.

The AD8195 Transmitter should be able to drive approximately 6 meters of HDMI cable @ 2.25Gbps resolution rates. Please refer to page 10 of the AD8195 datasheet:

http://www.analog.com/static/imported-files/data_sheets/AD8195.pdf

And also refer below schematics.

PDF

Note: Not all HDMI cables have the same insertion loss profile over similar distance so performance may vary between different cables.

Thanks,

Poornima

Hi,

DDC: Display Data Channel, one of the channels in an HDMI connection. DDC allows devices to assess each others’ capabilities and adjust themselves accordingly. For example, a DVD player can discover the maximum resolution of the monitor it is connected to by reading the monitor’s EDID chip and optimize its signal output to match that monitor’s display capabilities.

The AD8195 Transmitter should be able to drive approximately 6 meters of HDMI cable @ 2.25Gbps resolution rates. Please refer to page 10 of the AD8195 datasheet:

http://www.analog.com/static/imported-files/data_sheets/AD8195.pdf

And also refer below schematics.

PDF

Note: Not all HDMI cables have the same insertion loss profile over similar distance so performance may vary between different cables.

Thanks,

Poornima