Pandora Information On The Pandora''''s Ext Port.

[ashaw]

I have had to change a few things for manafactuarability reasons,

the new pdf can be found at.

http://www.alexisshaw.com/voltageconvertor2.pdf

 

[Squidge]

Truly WTF/Hard to believe. That PCB is fully SMD with 4 layers (if i read the pdf correctly - took a while to
4 layers? Are you serious? (I've not looked at the PDF yet) We have never needed more than 2 layers at work for any of our designs in the last 9 years.

Can the OP post the source files?

 

[ashaw]

the source files are altium format, but if you are happy to use them I can send them through. the new version does not need 4 layers, 2 will do but It does need 3 mil space / trace. this is because of the 0.5mm bga part used for the convertor to allow the use of a 16 pin dip socket.

I have done what i think will be the final revision of this board. waiting from the board house for a quote.

Top layer 3 mil space / trace.

Bottom layer 6 mil space/trace.

10mil hole / 20 mil diameter vias connecting gnd planes.

output voltage switchable between 3.3V and 5 V

Using MAX1722 step up convertor.

above PDF updated.

 

[EdCa22]

Looks fine to me, and a great piece of work - well done! I would hope you are going to make a couple to test first before ordering that many, just in case something goes wrong!? You can get small quantities made and assembled for you at some board houses - they use spare space/cut-offs from larger boards. Look up 'PCB pool'. It's more expensive than doing lots, obviously, but generally worth it unless you're 100% sure everything's okay.

Also, thought I'd share my method of doing SMT work at home- I use solder paste and a heat gun. You get a tiny piece of solder paste onto each pad and then put the components on with a pair of tweezers. Its great because if you screw up you can just wipe it all off and start again. When you're ready and its set up perfectly you just use the heat gun and its done. I've even done the odd BGA part like this but that was very hard (impossible with an iron though). I've found it much easier than the alternatives I've tried - soldering each pin one by one (which always goes wrong) or spreading solder over the whole chip and then removing excess with solder wick.

 

[ashaw]

i do not think that PCB pool is possible with this part, the tolerances required are too high, but I will do a prototype. An assembly house i think is required here methinks.

I am sorry but I do not think that you understand quite how small this PCB actually is in real terms.

 

[Squidge]

the source files are altium format, but if you are happy to use them I can send them through. the new version does not need 4 layers, 2 will do but It does need 3 mil space / trace. this is because of the 0.5mm bga part used for he convertor to allow the use of a 16 pin dip socket.

Protel DXP? I use the 2004 version, so if its that version or earlier, then I wouldn't mind

 

[ashaw]

i use Altium designer 2009 but i can export to the previous version, The student version is actually very affordable, so I jumped on the opportunity.

 

[MWeston]

I just don't think there will be much room for big mods like this, especially 30x40mm boards!

Here's a picture to show any empty space inside:
CODE
http://i198.photobucket.com/albums/aa99/MWeston_2007/pandora_space.png


I can PM you the pinout of the connector leaving the PCB if you really want it though. It's pretty cramped in the lid too. We didn't want the Pandora to get any bigger than necessary so all available space was attempted to be used as much as possible.

 

[ashaw]

well first of all this board is 10.15 mm by 20.3mm which is much smaller than 30mmx40mm. secondly this is intended for external mods. for internal mods I can make things much more dense than this. this board is actually very sparse.

 

[vega01]

I can PM you the pinout of the connector leaving the PCB if you really want it though.

I would be grateful if you could PM me the pinout! Thanks!

 

[ashaw]

Oh I have just started working on reducing the size of the board and I am certain I can make this the size of a 16 pin shrink dip package. that is 572 mil x 390 mil, so about 14.5 mm x 9.9mm.

Edit.

Confirmed, this part will have the form factor of a 16 pin SPDIP that is a 70 mil dip case.

Size 572 mil x 390 mil

Finished PCB, 2 layer 3mil trace/space.

Inlcudes schematic.
http://www.alexisshaw.com/voltageconvertor3.pdf
I am getting a quote for the The PCB's and Assembly. should have them soon.
Looks very much like the price will be close to $20 from what I am hearing at this time.

I just got back a quote for the PCB's

http://www.alexisshaw.com/pcbquote.pdf

Recieved a quote for the Assembly.

A full price breakdown can be found at:

http://www.alexisshaw.com/BOM.pdf

Have posted a poll in Top of forum

 

[MWeston]

well first of all this board is 10.15 mm by 20.3mm which is much smaller than 30mmx40mm. secondly this is intended for external mods. for internal mods I can make things much more dense than this. this board is actually very sparse.

Sorry, I thought I was replying to the fellow working on the breakout board for the LCD connector. I goofed. Your design is totally an external one so please disregard.