DS90UB925Q-Q1: Using FPD Link SERDES(DS90UB925Q or others) as generic SERDES components

Tsvetan Ginin

Hello,
from a technical point of view, is it possible to use all inputs of high-speed SerDes (for example, those of the FPD-Link III LVDS - DS90UB92x series), regardless of whether they are RGB or I2S, as digital IOs? My goal is to galvanically isolate the digital I/Os of the MCU from powerful motor drivers. What galvanically isolated LVDS buffer can I use for isolation?

Best regards,

Tsvetan Ginin

1 month ago

0 Esther Chang 1 month ago

TI__Mastermind 18900 points

Hi Tsvetan,

Thanks for the question. Based on my understanding, do you want to prevent ground shift between the SER and DES board over a cable? Can you provide a block diagram of your system?
BR,

Esther

0 Tsvetan Ginin 1 month ago in reply to Esther Chang

Intellectual 490 points

Hi Esther,

That's right. The diagram below shows the idea. I just don't know if the idea is feasible and what kind of bandwidth isolator I would need?

0 Esther Chang 1 month ago in reply to Tsvetan Ginin

TI__Mastermind 18900 points

Hi Tsvetan,

Let me talk to the internal team about this application and get back to you.

Thanks for your patience,

Esther

0 Esther Chang 1 month ago in reply to Esther Chang

TI__Mastermind 18900 points

Hi Tsvetan,

Thank you for your patience. On the FPD-Link, we cannot implement an isolated LVDS buffer that can filter the ground shift on the cable in between the two boards. However, an alternative approach can be adding ground islands between the FPD-Link connector and the rest of the GND on the SER and DES board, connecting AC coupling capacitors in between to filter the DC shift.

BR,

Esther

0 Tsvetan Ginin 1 month ago in reply to Esther Chang

Intellectual 490 points

Thank you, Esther, for the care and attention. Could you provide a block diagram of this system?

+1 Esther Chang 1 month ago in reply to Tsvetan Ginin

TI__Mastermind 18900 points

Hi Tsvetan,

This would be the implementation of a GND island.

BR,

Esther

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DS90UB925Q-Q1: Using FPD Link SERDES(DS90UB925Q or others) as generic SERDES components