A bit off topic, but I recently tried to order a few more DS1511Y RTC chips, but alas... Mouser has no stock until later this year. So... I found an ebay source (I know... don't go there). Bought three of them... when they came in, they didn't look right... instead of the usual IC-type pins out the bottom, they were wires... albeit the wrong spacing, they didn't quite fit the standard 28-pin DIP socket. Worse yet, they didn't work... I was able to set the date/time, but nothing happened... meaning the RTC did not increment time, so they were useless. The ebay source credited me (PayPal) and didn't even ask to have them shipped back.

So... next source... found them at Jameco. I've always found them to be a good reliable source... even visited them back in the 80's during a business trip out there and bought a bunch of parts... some still in their original Jameco packaging. In any case, I bought three DS1511Y chips from them... they look authentic, fit in the DIP socket perfectly. Unfortunately, only one works... I can read and write the NVRAM on all three, plus set the time and date. However, only one of them has a running clock that increments the time... the other two are static... whatever data I load, just stays there, no incrementing.

So... I'll contact James and see what he says. I guess I'll just have to bite the bullet and stick with Mouser, they've never let me down... yet!

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Regards, KM
https://github.com/floobydust

You could try going to Maxim's site and placing an order for a sample.

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

FWIW, Digikey lists that part as obsolete.

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In 1988 my 65C02 got six new registers and 44 new full-speed instructions!
https://laughtonelectronics.com/Arcana/ ... mmary.html

Yes... looked there too... Maxim shows 0 stock, but are showing Mouser as having 290.... but at Mouser, they show 290 expected in on 6/24/2021. I'll get two more on order.... and hopefully get them (as Jeff just posted, apparently they are going away).

Already heard back from Jameco... as they have discontinued carrying these, they are going to credit me for the two RTCs not working... and they don't want the bad ones back.

I'm thinking about pulling on of these bad ones apart... from what I can tell, the DS1511Y is basically a DS1501 (you can see a standard DIP-28 package from underneath). Pins 2 and 3 are likely bent upwards and the crystal wired in, and the same for pin 25 for the battery positive and a short lead from the negative to pin 14. Just not sure how much epoxy they squirted into the top cover. But if I'm correct on how they make the DS1511, one could easily make their own... and just make a 3D printed cover to put over it.

Based on 5-volts starting to go away... my next design will be based on 3.3V parts and mostly SMT as well. Sign of the times. I don't want to burn any time in sorting out older stock parts at this point, so time to move on to newer (and smaller) parts.

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Regards, KM
https://github.com/floobydust

What were the dates on the ones you got from ebay and Jameco?

Possibly the internal batteries have gone flat?

I've had luck with getting similar units off eBay in the past. Even with 10-15 year old date codes they have worked fine (still are 5-6 years later).

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Bill

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

So, the ones from Ebay are definite counterfeit. Here's a few pics showing the differences between one of those and my original new RTC I bought from Mouser a year or so ago. The real one is top of photos. Note that difference in the pins and the fact that the fake is just wires poking out from epoxy.







Here's a pic showing one of the RTCs from Jameco... a bit tough to read the print, but they appear to be original, despite the missing "dot" showing pin 1.... and all had the exact same codes/numbers on them.



I also looked at the status register and it shows that the battery is okay, so perhaps the oscillator is simply not running. I suppose that the crystal might have been damaged from excessive physical shock, but who knows.

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Regards, KM
https://github.com/floobydust

Well, Mouser has just received more stock of the Maxim DS1511Y+ RTC chips in. They show as stock of 288, as I ordered 2 more recently, which are showing as shipped now... once I'm back home (mid next week) I'll check them out... should be fine I'm thinking.

In any case, for anyone who is looking to use these in a design (or need some backup stock), best get them now.... before they disappear.

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Regards, KM
https://github.com/floobydust

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x86?  We ain't got no x86.  We don't NEED no stinking x86!