TFP410: How can we optimize the signal from TFP410?

Matthew Chen

Part Number: TFP410

Hi team,

My customer convert the input 24bit RGB signal to DVI by TFP410. The consistency test of TFP410 is failed. See the differential signal D0/1/2 in the picture. It can't work when we try to change the differential signal amplitude by adjusting the resistance of TFADJ pin. The length of the DVI differential signal from the pins of the TFP410 to the connector is about 3300 mils, and the internal length difference is within 30 mils.

Do you have any suggestion to optimize the signal ?

Thanks a lot

Matthew

over 4 years ago

0 David (ASIC) Liu over 4 years ago

TI__Guru**** 189901 points

Matthew

Is this the same design which they are using wires to connect from the TFP410 to the connector output?

Thanks

David

0 Matthew Chen over 4 years ago in reply to David (ASIC) Liu

TI__Intellectual 1530 points

Hi David,

No, it a question from another customer.

Thanks

Matthew

0 David (ASIC) Liu over 4 years ago in reply to Matthew Chen

TI__Guru**** 189901 points

Matthew

Can you please share their schematic, layout, and test setup?

The eye itself is under-equalized, so the loss of 3300 mils may be too much. In the datasheet, we recommend keeping each differential trace be as short as possible (< 2 inches is preferable) with no 90° angles.

Thanks

David

0 Matthew Chen over 4 years ago in reply to David (ASIC) Liu

TI__Intellectual 1530 points

Hi David,

Please see the SCH below. Could you move this thread to internal forum?

TFP410

Thanks a lot

Matthew

0 David (ASIC) Liu over 4 years ago in reply to Matthew Chen

TI__Guru**** 189901 points

Matthew

You can send me the layout in a private message as I can't move this thread to the internal forum.

Looking at the schematic, what common mode choke are they using and does it have sufficient bandwidth for their application required data rate. They can try to remove the choke and replace it with 0-ohm resistor to see if it helps to improve the eye.

Thanks

David

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TFP410: How can we optimize the signal from TFP410?