The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
Reply-To: "fred bartoli"
From: "fred bartoli"
Subject: Re: SPICE model of XTAL
Date: Mon, 9 Dec 2002 20:27:38 +0100
X-Newsreader: Microsoft Outlook Express 5.00.2314.1300
Organization: Guest of ProXad - France
NNTP-Posting-Date: 09 Dec 2002 20:24:32 MET
Tom Bruhns a écrit dans le message :
> Paul Burridge wrote in message
> > Well there's definitely a generic xtal in the parts list. I'd have
> > thought one could have entered a value for resonant frequency, but
> > strangely it appears not.
> That would be a really thin model of a crystal! The one Kevin
> mentioned, with a series RLC and a shunt C across it, is kind of a
> bare minimum, and it can be helpful to actually use multiple series
> RLCs to represent the various resonances (especially the overtones,
> but perhaps also spurious resonances near the fundamental). These are
> things they may not tell you when you buy the crystal, though. There
> have been articles about how to measure crystals in the ARRL
> literature. I think Wes Hayward is one of the fellows who put
> together a crystal test set, and he's available on the web. He
> frequents rec.radio.amateur.homebrew.
> Be careful: SPICE is NOT a valid excuse for not understanding how
> something works.
IMO it's the worst excuse for not understanding how circuits works, as it
allow you to play ad nauseum with parasitics and what-if scenarios.
Spices limitations, as you tell bellow, are an invitation to clearly
understand what is important and what is not because you can't model *all*
the phenomenons and so are to be selective on the relevant ones.
A bad model is almost certainly going to give you
> bad results, and SPICE adds a layer of other things (operating
> parameters and limitations) you need to be aware of over the top of
> the electronics you're trying to simulate.
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup