0603 size has a somewhat higher inductance, so it may not perform as well as 0402. Whether that's significant, I don't know.
Soldering 0402 has one advantage though: after you pick and place 10000 of them, suddenly 0603 seem as huge as bricks.
Topic: [ANN] Bitfury is looking for alpha-testers of first chips! FREE MONEY HERE! - page 19. (Read 176728 times)
September 06, 2013, 09:33:20 AM
September 06, 2013, 09:29:25 AM
since we're on the topic - I'm assume switching to 0603 size caps doesn't pose a problem, correct?
After hand soldering 150 0402 caps, I'm ready to not ever do that again
After hand soldering 150 0402 caps, I'm ready to not ever do that again
September 06, 2013, 09:11:25 AM
Right. You can't have too much overkill.
September 06, 2013, 09:07:15 AM
Maybe add a solder jumper from INCLK to GND.
As far as calculating bypass caps, to do a proper job you need to know the layout of the board and the exact specifications of the capacitor. As they say: "ain't nobody got time for that!"
As far as calculating bypass caps, to do a proper job you need to know the layout of the board and the exact specifications of the capacitor. As they say: "ain't nobody got time for that!"
Or, just overkill the hell out of it
September 06, 2013, 03:19:44 AM
Maybe add a solder jumper from INCLK to GND.
As far as calculating bypass caps, to do a proper job you need to know the layout of the board and the exact specifications of the capacitor. As they say: "ain't nobody got time for that!"
As far as calculating bypass caps, to do a proper job you need to know the layout of the board and the exact specifications of the capacitor. As they say: "ain't nobody got time for that!"
September 06, 2013, 03:15:34 AM
This is my first attempt at a single-chip schematic. No joke, I was more or less copying the c-scape design for their initial test PCB. Electrically I think this is all correct? I'm going with the same decoupling capacitor values* that were mentioned in a post by intron.
Looks fine. Toch?
intron
September 06, 2013, 12:45:33 AM
This is my first attempt at a single-chip schematic. No joke, I was more or less copying the c-scape design for their initial test PCB. Electrically I think this is all correct? I'm going with the same decoupling capacitor values* that were mentioned in a post by intron.
I couldn't figure out how to add a ground pad for the 5GHash chip but in the PCB design phase I'm going to have a copper net underneath the chip with vias to the ground plane for heatsinking and ground purposes.
I plan on using a 4-pin female molex connector to provide ground/VDD/IOVDD and a 8-pin header for the various I/O pins. After I layout this I'll have a second PCB with dc-dc converters to provide IOVDD and VDD. That same PCB will have the level-shifter to shift the spi signal voltages between the Raspberry Pi and 5GHash voltages.
My goal is to dip my toes into this to see if I enjoy it. So far I do but I haven't had to debug anything yet
I'd like to chain 2 of these together and then build a 2 or 4 chip PCB using the lessons learned from this project.
*- I found a couple very interesting PDFs on calculating the decoupling capacitance and the resulting inductance. Still educating myself on this so I decided to go with values that have been proven to work.
I couldn't figure out how to add a ground pad for the 5GHash chip but in the PCB design phase I'm going to have a copper net underneath the chip with vias to the ground plane for heatsinking and ground purposes.
I plan on using a 4-pin female molex connector to provide ground/VDD/IOVDD and a 8-pin header for the various I/O pins. After I layout this I'll have a second PCB with dc-dc converters to provide IOVDD and VDD. That same PCB will have the level-shifter to shift the spi signal voltages between the Raspberry Pi and 5GHash voltages.
My goal is to dip my toes into this to see if I enjoy it. So far I do but I haven't had to debug anything yet
I'd like to chain 2 of these together and then build a 2 or 4 chip PCB using the lessons learned from this project.*- I found a couple very interesting PDFs on calculating the decoupling capacitance and the resulting inductance. Still educating myself on this so I decided to go with values that have been proven to work.
September 05, 2013, 05:10:35 PM
Thanks for the info...
I've already got 100 of these boards being fabbed, but I'll take all this into consideration for the next iteration
Assuming they work, and assuming I can get the heat out of them, and assuming I can get chips, yes
If you're interested in bare boards for DIY, lemme know in pm
September 05, 2013, 05:02:50 PM
I can't help wondering though, has anyone had success with fewer, larger caps? From what I can see, all the grounds are on the centre pad, all the pins on 3-sides are commoned internally to VDD, then split out to dozens of tiny caps, via'ed down to the ground plane. Does this have some inductance or ESR benefit, are the caps just cheaper, or is this just a design that works, so why mess with it?
More little caps in parallel have lower inductance than a few big ones. Maybe 15 caps is overkill, but it works, so why mess with it ?
I could try mounting fewer, but the problem is that if it doesn't work properly, I'd have to hand solder the rest, which is a terrible job.
Fair enough!
Cheers.
September 05, 2013, 04:29:46 PM
Thanks for the info...
I've already got 100 of these boards being fabbed, but I'll take all this into consideration for the next iteration
September 05, 2013, 04:27:33 PM
Could you change your mountingholes to 3.18 mm? I have never seen any smaller mountingholes than M2,5 on electric equipment.
We could offer you an individual water cooler with a size of 100x30x15mm (2 x 1/8 "fittings) ~ 40 € each (> 100)
Are you planning to design another backplane for water cooler?
If yes, i have some suggestions: Try to put more boards on one cooler. Use the front and the backside of the watercooler.
2 short examples:
If you use front and back of the watercooler, the cost per board would only be --> 20 €
If you manage to put 4 boards on a 100x70x15 (2x G1/4" fittings) watercooler ~ 50 € (> 100pieces)
the cost per board would decrease even further. --> 12,50€ per Board.
Another idea is to use multiconnectors from watercooling for grafic-cards.
But i think the small extra-chip with the ?40A regulator? will prevent all this.
example:
2xBitburner XX with one watercooler http://www.anfi-tec.de/forenbilder/13.07.11%20Bitburner/Anfi-tec%20Bitburner%20XX%201.JPG
finished blocks http://www.anfi-tec.de/forenbilder/C006/13.08.30%20Bitburner%20Waterblocks.JPG
And of course with less coolers you have to do less tubing.
Regards Andre
Thanks for the info...
I've already got 100 of these boards being fabbed, but I'll take all this into consideration for the next iteration
September 05, 2013, 04:13:55 PM
I can't help wondering though, has anyone had success with fewer, larger caps? From what I can see, all the grounds are on the centre pad, all the pins on 3-sides are commoned internally to VDD, then split out to dozens of tiny caps, via'ed down to the ground plane. Does this have some inductance or ESR benefit, are the caps just cheaper, or is this just a design that works, so why mess with it?
More little caps in parallel have lower inductance than a few big ones. Maybe 15 caps is overkill, but it works, so why mess with it ?
I could try mounting fewer, but the problem is that if it doesn't work properly, I'd have to hand solder the rest, which is a terrible job.
September 05, 2013, 03:59:46 PM
That is beautiful work
I can't help wondering though, has anyone had success with fewer, larger caps? From what I can see, all the grounds are on the centre pad, all the pins on 3-sides are commoned internally to VDD, then split out to dozens of tiny caps, via'ed down to the ground plane. Does this have some inductance or ESR benefit, are the caps just cheaper, or is this just a design that works, so why mess with it?
September 05, 2013, 02:13:55 PM
Designed to have a heatsink mounted to the back with airflow; I expect this sucker to require some cooling!
If you want to overclock them and expect to much heat, please feel welcome to contact us (anfi-tec) for some watercoolers.Furthermore for a better packing density.
That might be a good option... I'd need a waterblock that's about 100x30mm.
- what do you think will the 12 chips produce in heat/Power consumption in idle?
- and the same with overclocking?
- how many of these miniboards you plan to put on a backplane/rack?
- what distance is planned for the pci-slots (with watercooling you can pack them much closer together than with aircooling)
- are you planing to sell these miniboards?
- cooling from the backside of the board like the avalonchips?
12 chips at full rate will produce around 30W. The 40A regulator probably another 5W.
The bottom of the module has the soldermask masked back to show bare plated copper for good heat transfer. Yes, cooling from the backside of the board.
Heatsink dimension should be 100x35mm. I'll get you the mounting hole pattern this evening; they're 2mm mounting holes.
For the backplanes I'm designing now (for aircooling), the slots are 36mm apart. Here's a render of a 480GH miner on a 16 way backplane:
http://www.prototechnical.com/~imcmahon/480GH_render1.png
We could offer you an individual water cooler with a size of 100x30x15mm (2 x 1/8 "fittings) ~ 40 € each (> 100)
Are you planning to design another backplane for water cooler?
If yes, i have some suggestions: Try to put more boards on one cooler. Use the front and the backside of the watercooler.
2 short examples:
If you use front and back of the watercooler, the cost per board would only be --> 20 €
If you manage to put 4 boards on a 100x70x15 (2x G1/4" fittings) watercooler ~ 50 € (> 100pieces)
the cost per board would decrease even further. --> 12,50€ per Board.
Another idea is to use multiconnectors from watercooling for grafic-cards.
But i think the small extra-chip with the ?40A regulator? will prevent all this.
example:
2xBitburner XX with one watercooler http://www.anfi-tec.de/forenbilder/13.07.11%20Bitburner/Anfi-tec%20Bitburner%20XX%201.JPG
finished blocks http://www.anfi-tec.de/forenbilder/C006/13.08.30%20Bitburner%20Waterblocks.JPG
And of course with less coolers you have to do less tubing.
@cscape
for you the same: If you want to overclock them and expect to much heat, please feel welcome to contact us (anfi-tec) for some watercoolers.
Regards Andre
September 05, 2013, 11:18:23 AM
Insanely small parts... I can barely see them when looking through a magnifying lens...
spiccioli
September 05, 2013, 10:56:10 AM
Here's a couple of photo's I took while assembling an S-HASH board.
Perler Beads for Adults!
September 05, 2013, 10:47:42 AM
You do that by hand?
??
how long does it take? flippin` ek. I could not do that
Yes, but only for small series, like one or two prototypes. This is a board for Foofighter to help fit a case for it. ??how long does it take? flippin` ek. I could not do that
I also made these boards (in Dave's first post) in a similar way.
mega props dude. seriously
September 05, 2013, 10:41:31 AM
You do that by hand???
how long does it take? flippin` ek. I could not do that
Yes, but only for small series, like one or two prototypes. This is a board for Foofighter to help fit a case for it. ??how long does it take? flippin` ek. I could not do that
I also made these boards (in Dave's first post) in a similar way.
September 05, 2013, 10:39:51 AM
Here's a couple of photo's I took while assembling an S-HASH board.
beautiful pics!
aah, the tiny zen of electronics assembly ...
September 05, 2013, 10:35:01 AM
You do that by hand?
??how long does it take? flippin` ek. I could not do that
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