Replacement options: 512k x 16 SRAM

[Guest]

I've looked high and low with no luck so far....

The current part is:

Samsung K6X8016C3B
512k x 16 asynchronous SRAM
55 ns
5 volt
TSOP2 44 pin package.

It is being discontinued, and I need a replacement part which is drop-in
compatible for an ancient product which we still sadly manufacture and
repair.

Anyone have any suggestions?

 

[Jim Thompson]

I've looked high and low with no luck so far....

The current part is:

Samsung K6X8016C3B
512k x 16 asynchronous SRAM
55 ns
5 volt
TSOP2 44 pin package.

It is being discontinued, and I need a replacement part which is drop-in
compatible for an ancient product which we still sadly manufacture and
repair.

Anyone have any suggestions?

I've never specifically been involved with memory chips, but in a few
similar analog situations I've made up small "daughter" boards to
adapt incompatible pin-outs.

...Jim Thompson

 

[Joerg]

Hello Jim,

I've never specifically been involved with memory chips, but in a few
similar analog situations I've made up small "daughter" boards to
adapt incompatible pin-outs.

Works with digital, too. But it requires writing a whole big ECO and
sometimes the timing is critical. There were situations where newer
chips that were too fast made it hick up. That doesn't exactly speak for
a good design but when it's OEM you've got to deal with it.

Anyway, Aaron, you said "being discontinued". If that means you just
heard the clang of the last order bell this would be the time to
stockpile. Else it's off to the obsolete part vendors and then it gets
expensive.

Curious: Why are these SRAM chips failing in the first place? I have
never had one fail since I was in diapers ;-)

 

[DJ Delorie]

It is being discontinued, and I need a replacement part which is drop-in
compatible for an ancient product which we still sadly manufacture and
repair.

I don't know about drop-in, but look at Cypress's CY7C1041B. It's
smaller, but nearly pin compatible. Cypress may have a 512kx16 that
fits.

 

[Gary Pace]

I've looked high and low with no luck so far....

The current part is:

Samsung K6X8016C3B
512k x 16 asynchronous SRAM
55 ns
5 volt
TSOP2 44 pin package.

It is being discontinued, and I need a replacement part which is drop-in
compatible for an ancient product which we still sadly manufacture and
repair.

Anyone have any suggestions?

ISSI make the following 512k x 16 in TSOP2-44 :
IS61LV51216 (I use this one)
IS62WV51216ALL
IS62WV51216BLL

A quick glance at the data sheets seems to show them as compatible

I had quick look round some disties and the first and last one are stocked
by a few.

 

[Guest]

Hello Jim,


Works with digital, too. But it requires writing a whole big ECO and
sometimes the timing is critical. There were situations where newer
chips that were too fast made it hick up. That doesn't exactly speak for
a good design but when it's OEM you've got to deal with it.

Anyway, Aaron, you said "being discontinued". If that means you just
heard the clang of the last order bell this would be the time to
stockpile. Else it's off to the obsolete part vendors and then it gets
expensive.

That is basically it... we're trying to buy up what we can, but as we only
sell about 50 units a year we hate to keep thousands on the shelf.

Curious: Why are these SRAM chips failing in the first place? I have
never had one fail since I was in diapers ;-)

They aren't failing - the whole board fails and need to be replaced, which
necessitates that we keep making a small number of them for replacements. As
for why the boards fail... lets just say these are usually used in a "shop
floor" environment.

 

[Guest]

ISSI make the following 512k x 16 in TSOP2-44 :
IS61LV51216 (I use this one)
IS62WV51216ALL
IS62WV51216BLL

A quick glance at the data sheets seems to show them as compatible

I had quick look round some disties and the first and last one are stocked
by a few.

Those are all non 5 volt parts... BSI appears to have something that will do
the trick though - at least until they discontinue it.