Comments & Questions for Parallella Board - Power Supply

[Sundance]

Hi,

Very impressive - and the USD99.00 is now a ridicules price! Thanks to Xilinx as well.

Questions:
What is the estimated power required now with a Z7020?

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Request:
I suggest that you route 5V to the Mouting holes. We have done this for years and it has many benefits for doing "Embedded Systems" and has no extra cost.

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Comments:
Suggest that you provide a Link to a PSU from Digikey. Can be sourced World-Wide and might not be the cheapest source, but it will arrive the day after

Flemming

[tnt]

That seems like a terrible idea ... that means that to mount it to some metal enclosure you would need to be careful about using isolation.

[Sundance]

[tnt]

[aolofsson]

Flemming, This is a cool idea. Certainly for stacking up system it certainly would be a very slick power delivery system.

tnt, Thanks for presenting the other side of the equation! Very valid points. We don't want people to burn up their boards because they missed reading parts of the manual.

Once we release the rest of the specs tomorrow, we should continue the discussion.

[tnt]

One idea would be to have 3 mounting hole grounded, then leave the one near the 5V supply unconnected by default, but have
the option to fit a jumper, or a solder bridge. There seem to be a bit of space in that corner.

This way by default it's "safe", but if you know what you're doing you just have to add a jumper / solder bridge which should be quick and easy enough.

[tnt]

Note that in the same "safety" territory, you don't want the board to be fully symmetrical, to make sure you can't plug it the wrong way in an expension board. I don't know how symmetrical the samtec connectors are, but definitely something to consider.

[aolofsson]

Yes, a friend brought up that point during the design process already and we listened.

[Folknology]

You can use appropriately rated Schottky diodes from the 5v mounting holes to the internal +v supply if you want safe, and of course you would prob only use 2 of mounting holes at one for this purpose, the others should be grounded.

regards
Al

[ESI]

Is JTAG supported somehow?
Maybe through one of the USB?
I am working with ZC7020 and it gets easily bricked, when you work "bare metal".