Async FIFO chips?

[Tim Watts]

Hi,

I saw a rather interesting Elektor article (Feb 2003) for building a cheap
40MHz logic analyser using an AVR and one or more 9 bit FIFOs with storage
for many kilo words.

The chips in question were the IDT720x series or their Cypress version the
CY7C462 and friends.

Had it in mind to build one of these next year (hobby, not production), but
the IDT and CY chips seem to have become seriously discontinued in DIP
format - Digikey are down to the last 18 of one of the IDT chips and most of
the rest are unavailable.

Anyone know of any other async fifo memory chips? I've hunted and those
seemed to be the only ones in that class. Looking for:

4+ bits wide (could manage with 1 bit devices);
40+MHz clock
at least 4k words, 16k better.
DIP package.

I know chips go obselete, but it seems weird for a whole class to disappear
(or at least be only available in SMT format - I prefer to socket my chips
and I'm not up on SMT soldering ).

Many thanks

Tim

 

[Tim Watts]

Jon Elson <[email protected]>
wibbled on Friday 19 February 2010 23:44

If they've got them in SMT, you can get adaptor boards to go from most
common SMT footprints to DIP. Soldering low-density SMT's isn't any big
deal, a small soldering tip and a little magnifier hood is all you need.

I suppose so, Jon.

I was browsing Farnell last night. Despite the fact you can now get 74HC4017
counters running at 83MHz for less pence than they cost when I was a kid in
1980, they *still* sell CD4017s. 741, 555 no problem.

I can understand a specific chip buggering off, but not a whole class of DIP
based large memory fast fifos, which seem more general purpose than
specialist... I found http://www.xs4all.nl/~ganswijk/chipdir/ and so far
haven't found anything in the fifo section that's still in stock (haven't
got to the end mind).