GT Transceiver Power

[obverse]

I read in one of the User Guides that GT transceivers should have their own dedicated power supplies. An upcoming design will use 3 Ultrascale+ parts and I was wondering do I need to have separate GT power supplies for each chip or can I supply just the tranceivers for all chips with one dedicated supply?

Thanks dor the help.

[drjohnsmith]

No reason why you can't
BUT:
The GT supplies need to be incredibly close tolerance and low noise,
You might be able to save by having one supply for all three devices, but your on your own if you have problems on the GT links, debugging power problems is incredibly hard,

Id also think that one supply for all three will be a DCDC, due to the power needed, and keeping their noise off the GT is difficult with a big DCDC.

So, yes you could , but its going to be hard and higher risk than individual supplies.

[borisq]

hi @obverse 

if there are multiple chips on the board, the MGT power supplies for each rail can be shared.

for example, MGTAVCC of all chips can be shared.

You can use XPE spreadsheet to estimate the power comsumption for each chip.

Thanks,

Boris 

[obverse]

Thanks to those who responede.