[time-nuts] Simulation

[Didier Juges]

Actually this is a good argument FOR modeling well applied because you can simulate parts that you cannot buy today but that your vendor will ship under the same part number a few years down the road. Try doing that in the lab...

I have experienced it so many times it's not even funny. And that includes parts bought against SMD (Standard Military Drawings) which tend to have more complete specs than the commercial parts they target.

Another area is simulating the effects or radiations. Quite expensive to do in practice, when it's even practical.

On the other hand, if the model does not work like the hardware, don't look for what's wrong with the hardware :)

Always get the model to work like the hardware before you make changes.

Didier

Famous last words: "But the prototype worked so well."

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

-----Original Message-----
From: Bob Camp <lists at rtty.us>
Sender: time-nuts-bounces at febo.com
Date: Sat, 14 Aug 2010 08:30:29 
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: [time-nuts] Simulation


Hi

Simply a few stories I thought I would share.

Simulate design. Use manufacturer's published models. Build design. Note differences. Call manufacturer. Answer - switched die three years ago, Ft is now " much better " ( now 3x old parts ).

Odd they never mentioned that to people who work for the same company.

Simulate design, Build design, verify design, ship it for a few years. Odd things start to happen. Look at some parts. Package looks different. Ask around..... Line got moved to other side of big ocean. Process got " tweaked" beta is now 4x what it was.

Again all inside the same company. Both cases were excused by industry standard specs that had no upper limit.

We had whole departments devoted to tracking this sort of stuff. It still happened on a regular basis. 30 years later the specs on the devices and their published models are still the " old version " ones.

Bob 


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