[time-nuts] Simulation

Didier Juges didier at cox.net
Sat Aug 14 18:12:14 UTC 2010


Mil specs cover a number of things that are not always in the commercial specs, but not always, and mil spec parts are going the way of the dodo. Nobody wants to make them, except the local garage shop which does not mind selling you $0.02 parts for $60 (quite common) and the worst is that these parts are often made in very small runs from the old masks, or they are custom packaged dies bought from commercial sources and screened to meet the requirements and end up having very poor reliability because the small runs do not allow the quality of commercial parts made in the gazillion.

Quite a paradox!!!

In my 30 years experience designing military and space hardware, I now believe the commercial grade plastic parts you get from Digikey are quite a bit better than the expensive mil spec ones in the hermetic packages, even when rated 0-70C and when used in a humid environment.

Of course, if you have to have hermetic parts to satisfy an explicit customer requirement, that's another story, even though I have been fairly successful at obtaining waivers from customers in that regard.

Didier

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Sent from my BlackBerry Wireless thingy while I do other things...

-----Original Message-----
From: Hal Murray <hmurray at megapathdsl.net>
Sender: time-nuts-bounces at febo.com
Date: Sat, 14 Aug 2010 10:17:32 
To: Discussion of precise time and frequency measurement<time-nuts at febo.com>
Reply-To: Discussion of precise time and frequency measurement
	<time-nuts at febo.com>
Subject: Re: [time-nuts] Simulation


> Line got moved to other side of big ocean. Process got " tweaked" beta is
> now 4x what it was.

I'm pretty sure that military grade parts have paperwork and processes to 
cover that case.  I expect it costs a lot.

I think the same sort of service is available to high volume customers at a 
less than military price.

Or, as Javier said:
> I periodically receive PCNs (product change notifications) from EBV
> Elektronik, which is a quite big european semiconductor distributor,  

So maybe it doesn't take a high volume, you just have to get plugged into the 
right paperwork flow and then read all the fine print to see if the change is 
interesting.



-- 
These are my opinions, not necessarily my employer's.  I hate spam.




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