Source for SDRAM chips

Embedded computer systems topics

Source for SDRAM chips

Postby Alex Parkinson » Fri Dec 24, 2004 10:23 pm

Does anyone know where small quantities of SDRAM chips (not modules) could be purchased?

Thanks,
Alex Parkinson
Alex Parkinson
 

Re: Source for SDRAM chips

Postby TCS » Sat Dec 25, 2004 4:40 am

On Fri, 24 Dec 2004 12:23:02 -0500, Alex Parkinson <ahparky@ufl.edu> wrote:
Does anyone know where small quantities of SDRAM chips (not modules) could be purchased?
yes.
TCS
 

Re: Source for SDRAM chips

Postby Earl Bollinger » Sat Dec 25, 2004 6:57 am

www.digikey.com comes to mind.
www.mouser.com
www.jameco.com
sometimes www.allelectronics.com and or www.bgmicro.com have them in too.
www.ebay.com sometimes has the chips for sale or auction too.


"Alex Parkinson" <ahparky@ufl.edu> wrote in message
news:cqhj9k$14jg$2@spnode25.nerdc.ufl.edu...
Does anyone know where small quantities of SDRAM chips (not modules) could
be purchased?

Thanks,
Alex Parkinson
Earl Bollinger
 

Re: Source for SDRAM chips

Postby Guest » Sat Dec 25, 2004 7:27 am

Are you looking for specific chips, or just any parts in approximately
the right density?

I had big trouble trying to source 1Mx16 SDRAMs for an ARM prototype
run we did about a year ago. I eventually cannibalized SODIMMs :(
Guest
 

Re: Source for SDRAM chips

Postby Richard H. » Sat Dec 25, 2004 7:56 am

Alex Parkinson wrote:
Does anyone know where small quantities of SDRAM
chips (not modules) could be purchased?

I've been able to source Micron's 256Mbit SDR DRAM from Arrow
electronics on one-off quantities for ~$10 ea. (MT48LC16M16A2TG-7E, the
4Mx16-bit version). They seem to have been on allocation forever, but
in small qty it hasn't been a problem.
Richard H.
 

Re: Source for SDRAM chips

Postby Wim Ton » Sat Dec 25, 2004 6:02 pm

"Alex Parkinson" <ahparky@ufl.edu> wrote in message
news:cqhj9k$14jg$2@spnode25.nerdc.ufl.edu...
Does anyone know where small quantities of SDRAM chips (not modules) could
be purchased?


In the UK: Farnell

Wim
Wim Ton
 

Re: Source for SDRAM chips

Postby Alex Parkinson » Mon Dec 27, 2004 7:34 pm

yes.

Thank you. That was very helpful.
Alex Parkinson
 

Re: Source for SDRAM chips

Postby Alex Parkinson » Mon Dec 27, 2004 7:43 pm

larwe@larwe.com wrote:
Are you looking for specific chips, or just any parts in approximately
the right density?

I'm not looking for any particular chips, mainly just anything at about 1M x 8 and up.
Alex Parkinson
 

Re: Source for SDRAM chips

Postby TCS » Mon Dec 27, 2004 10:22 pm

On Mon, 27 Dec 2004 09:43:37 -0500, Alex Parkinson <ahparky@ufl.edu> wrote:
larwe@larwe.com wrote:
Are you looking for specific chips, or just any parts in approximately
the right density?

I'm not looking for any particular chips, mainly just anything at about 1M x 8 and up.

what happened when you did web searches?
what did you find with mouser, digikey, and other vendors that you found
from your web search?
TCS
 

Re: Source for SDRAM chips

Postby Guest » Mon Dec 27, 2004 10:44 pm

No stock, or minimum purchase a waffle, for every single part number I
could find that was compatible with my design. Mostly it was no stock.
I eventually begged some samples out of Micron, I think.
Guest
 

Re: Source for SDRAM chips

Postby Alex Parkinson » Mon Dec 27, 2004 10:52 pm

what happened when you did web searches?
what did you find with mouser, digikey, and other vendors that you found
from your web search?

I haven't found anything with Digikey, Mouser, AvNet, Future, Allied, Newark, All
Electronics, or BG Micro. So far Arrow, which was suggested by Richard H., seems to be
the only major vendor that sells them in small quantities. I've seen them on eBay
before, but I'd like to find a source that's a little more reliable.
Alex Parkinson
 

Re: Source for SDRAM chips

Postby Richard H. » Tue Dec 28, 2004 3:51 am

Alex Parkinson wrote:
I haven't found anything with Digikey, Mouser,
AvNet, Future, Allied, Newark, All Electronics, or
BG Micro. So far Arrow, which was suggested by
Richard H., seems to be the only major vendor that
sells them in small quantities. I've seen them on
eBay before, but I'd like to find a source that's
a little more reliable.

I'm glad that pointer was useful. IIRC, I went about it the reverse
direction - asked the manufacturer who stocks their parts and sells qty
1. In fact, I think I was asking about samples sources. I stopped when
I found the first one, but you might try this with other manufacturers.

I got the sense that DRAM prices are too volatile for most distributors
to stock...

What quantities are you looking for? A TSSOP tray looks to be 108 pcs
(~USD$1000 for 32MB chips) - a bit much for hobby, but maybe not for
short-run production. Distributors might be more willing to broker full
trays.

Also, you might check with smaller shops that make products with similar
parts - they may be willing to sell you loose parts from their
inventory.
Richard H.
 

Re: Source for SDRAM chips

Postby Mike Harrison » Tue Dec 28, 2004 5:57 pm

On Mon, 27 Dec 2004 15:51:45 -0700, "Richard H." <rh86@no.spam> wrote:

Alex Parkinson wrote:
I haven't found anything with Digikey, Mouser,
AvNet, Future, Allied, Newark, All Electronics, or
BG Micro. So far Arrow, which was suggested by
Richard H., seems to be the only major vendor that
sells them in small quantities. I've seen them on
eBay before, but I'd like to find a source that's
a little more reliable.

I'm glad that pointer was useful. IIRC, I went about it the reverse
direction - asked the manufacturer who stocks their parts and sells qty
1. In fact, I think I was asking about samples sources. I stopped when
I found the first one, but you might try this with other manufacturers.

I got the sense that DRAM prices are too volatile for most distributors
to stock...

What quantities are you looking for? A TSSOP tray looks to be 108 pcs
(~USD$1000 for 32MB chips) - a bit much for hobby, but maybe not for
short-run production. Distributors might be more willing to broker full
trays.

Also, you might check with smaller shops that make products with similar
parts - they may be willing to sell you loose parts from their
inventory.

I think the main problem is that not many people these days use loose DRAM chips, as modules are so
widely available - for development quantities, it will often be easier and cheaper to strip chips
off a PC memory module where possible.
Mike Harrison
 

Re: Source for SDRAM chips

Postby Guest » Tue Dec 28, 2004 6:35 pm

If I have to do it again, I think I'll design in a SODIMM socket anyway
(at least for prototypes). Being able to upgrade the RAM ex post facto
is a Good Thing :)
Guest
 

Re: Source for SDRAM chips

Postby Richard H. » Tue Dec 28, 2004 10:54 pm

larwe@larwe.com wrote:
If I have to do it again, I think I'll design in a
SODIMM socket anyway (at least for prototypes).
Being able to upgrade the RAM ex post facto
is a Good Thing :)

Lewin,

When I last looked into this, I discovered SIMM sockets were very
expensive through the Usual Sources - ballpark USD$25. Even if the SDR
SIMM was free, the solution was much more expensive than just buying an
oversized chip. Have you found a source for SIMM & DIMM sockets that's
reasonably priced?

Also, you mention SODIMMs - are you using a DRAM controller? SDR seems
to be the end of the road without one (timing stability, clock speed,
etc.), but apparently they aren't available as discrete parts anymore -
know of any discrete DRAM controllers?

Richard
Richard H.
 

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