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Async FIFO chips?

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

Managers, politicians and environmentalists: Nature's carbon buffer.
Reply to
Tim Watts
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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.

Jon

Reply to
Jon Elson

Oh, and don't get me started on obsolete, hard to get, etc. stuff! YIKES! I design a prototype, and while buying the parts, notice Digi-Key has 40,000 pieces on hand. Ah, good supply, no problem. Then, I revise the board and order a bunch and go back to Digi-Key to get 100 pieces of the parts, suddenly they have no stock, its a discontinued part, AIEEEEE!!! And, I have 100 blank boards coming and can't get the chips anymore. Don't ask me how many times this has happened, it is driving me nuts! Or, I find that Digi-Key or other Distributor has placed a 2000-piece minimum order on the part, but they have 137 pieces showing as "in stock". How the HELL will they ever get those 137 pcs. off their shelves if they will only sell 2000-piece lots? Some of these are expensive parts, so you have to buy $25,000 lots or none. It is definitely making Digi-Key especially, pretty non-friendly to small manufacturers.

Jon

Reply to
Jon Elson

Jon Elson wibbled on Friday 19 February 2010 23:44

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

formatting link
and so far haven't found anything in the fifo section that's still in stock (haven't got to the end mind).

--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.
Reply to
Tim Watts

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