Topic: Klondike - 16 chip ASIC Open Source Board - Preliminary - page 164. (Read 435369 times)

Nice!
When do we get the communications protocol ?

Hi BkkCoins,
I think you need a Spartan-6 XC6SLX16, at least on multi-module systems. If not a Spartan-6, anything that can handle up to 32 high-speed serial ports asynchronously.

Please come over to my thread where I explain why I think 32 async serial ports are necessary: https://bitcointalk.org/index.php?topic=189976.60

The cluster of SMD resistors sounds very well to simulate the 2W of ASICs. For the purpose of reliability test there is not a hard requirement to simulate the ASIC because I need only to monitor the stability of 1.2V/3.3V outputs and the temp at the converters at full load; in order to get this I´ll need 20W of resistors and I´ll use a troughole array soldered to the output. After some tests I will find the max temperature when something go wrong or any component die.

I finally can open all the files. Thank you!

Let the race begin!!

Exciting... Avalon reference info just uploaded.

https://bitcointalksearch.org/topic/release-avalon-reference-200668

https://github.com/BitSyncom/avalon-ref

Now... if only they were so prompt with B3 

Sounds excellent, and more than I could do by myself here. Thank you.

Let me know what you think is best for an ASIC test pad on board. I was going to put a cluster of 4x 3 ohm 0.5W SMD 1210 pkg resistors on a 5x5mm pad with 5x5 thermal vias under, same as planned for main board. I could put one or two of these in the space remaining. Maybe that's pushing the resistor rating too much @ 0.48W but more qty won't fit as well. (4x 2.5x3.2mm)

btw, I pushed the pro (project file) for power board. See if that helps for opening schematic.

Looks like it will be 20 qty now then. My rough count now is that 16 are sold.

I will want one too, if you can.

Hi,

I will made a reliability test (stress test) because the power stage (DC-DC converters) is very critical. I will use a chamber for a thermal cycling test (http://www.thermalproductsolutions.com/products/productDetails.aspx?pcId=14&pscId=86&plId=30). I will use power resitors for test at full load. I will let you know the results.

Bkk I´m in for 5 test boards.

Ok, 1 for you and... they're gone.
If I get 4-5 more wanted then I'll bump to 20 total.

Count me in for 1 power supply test board.

I'm in for two PCBs if you can ship to the US, i'll send you a pm

hehe, if you send me a board with parts and such and sign it in a sharpie and write first! ill pay 12 plus shipping

I'll see if I have parts in time but I can send the board anyway. Cost would be $2 for board plus $3 reg mail postage. I haven't worked out parts cost but guessing it would likely be around $8, so say $10 total plus shpg. Anyway, don't rush as lots of time before the boards gets here and I'll add up parts cost.

I'll put some pins suitable for a breadboard so that it has some utility beyond testing.

I'll keep 4 for myself and offer up 6. 1 is taken plus 1 if you want. Leaves four 1 available.

edit: if more people want these then I can bump to 20 boards, but be aware these are test boards and the purpose is to see if there is issues with noise and layout.

Paypal ok. PM me for address.

I would be willing to give it a try can you sent the board and loose parts?
I will pay for them. Can you accept PayPal ?

You can just use New to create blank project file in the same directory. I should push the pro file anyway. I just looked in one and it seems to also track libraries and options, not just files. Will do.

I was looking to put SMD resistors hoping to get close to a similar thermal connection, mainly for seeing how well conduction to heat sink works and take temperature readinsg. It's not great as also it will be 2 layer instead of 4 and that will have some impact. I would expect 4 layer to perform better however. Maybe 8 placed 2 per side would be a closer simulation. That should fill in the 7x7mm almost completely. It's basically "free" in the sense I was doing the board and it has space and could be useful info.

To be honest i have not put much time or effort into the board design as i've been fairly busy and I'm waiting on the Avalon specs, but I was thinking features similar to what you find on a GPU for monitoring - measure 12V/3.3V/1.1V with an ADC and report, measure temperature in a few areas (buck converter, perhaps thermally connected to heatsink of a group of chips.

Also perhap slight changes if my local pcb assembly outsource-place would perfer/do it cheaper with say, all SMT components and no through hole, etc.



Awesome!

question though - I am not familar at all with kicad, but i downloaded a copy of your github and it seems like it only looks to open .pro project files and i didn't see any in there?

I may get the board fabbed with a U.S. company (thinking of advanced circuits but have a few places to throw quotes to)

I will look for a random 48-QFN (7x7mm) that would have close to the same thermal properties and power dissipation.  resistors are a good start, but the key part is the thermal conduction from the pad to the PCB and the PCB to whatever else

edit : small 'snag' in that plan - the only 48-QFN 7x7mm chip that burn more than 1W are.. you guessed it, high speed, fairly expensive ADCs.  same thing if you expand it to all *-QFN.

Instead you can grab a 0.50$ linear regulator in a TO-263/D2PAK and solder the tab to the QFN pad, then connect the output to a high wattage resistor and choose input DC so you can burn any wattage you want across the D2Pak (and easily calculate it based on Power=V*I)

something like one of these - and actually the higher the dropout voltage the better, the less current you have to pull through the regulator to burn a given wattage.

http://www.digikey.com/scripts/dksearch/dksus.dll?FV=fff40027%2Cfff80182%2C142c004d%2C142c0057%2C142c0091&vendor=0&mnonly=0&newproducts=0&ptm=0&fid=0&quantity=0&PV507=69&stock=1

Yes, Thanks. I made an error transcribing from schematic to parts list. Will update now.

Was planning to put an ASIC pad on power test board but with 4x 1/2W resistors on pad to simulate. I'm running a batch of 10 power test boards in the next day or two. roybitcoin wants to run tests on it as well. kicad files and gerbers for this already on github for preview, suggestions.

If someone else wants a board (for a small fee to cover costs) to build/test then let me know. This would be a 5x5cm 2 layer board with same parts layout for 1.2V+3.3V buck regs, along with heat sink test pad, and connectors. I may throw a PIC on the corner with break out since there seems to be room. It could be a handy power supply for breadboarding as well. I want to finish this and get it sent asap, even if it's a bit rough. Takes a week or two to come back.

Suggestion for testing - dedicate one (or a few) boards to thermal testing.  Populate with a QFN chip (doesn't matter what it does) that dissipates as much power as an avalon chip.  If possible, one that uses the same Vcc voltage as avalon (hence, same current draw and will also test the buck converter limits)

I will probably do this myself.. (but still waiting on the damn avalon specs!)

Small error on parts list R24 & R25 value = 2.2K ?

Yes. I'd been assuming USB wouldn't be populated  where unnecessary but that's probably not reasonable for pre-assembled boards. So it'll be better if I move the USB in slightly so it doesn't protrude. Either that or I'll work out an alternate layout that doesn't require face 2 face as shown. Thanks for bringing it to my attention - will give it some today.

edit: So I played around and came up with this alternate layout for tiling. Just mulling this over for now and if it's workable I'll go this way. Also updated for non-corner design. The usb <> power conn opposite-facing may be a issue and I'll take a close look and offset if need be.



Note that the K64 wouldn't have internal pin hdrs. I would wire those one in the board either as tracks or actual wires, depending on how I panellize (in gerbers or in brd design).