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.
From: "Klaus Vestergaard Kragelund"
Subject: Drift/Worst Case calculations of SMD Chip Resistors
Date: Wed, 2 Oct 2002 00:10:54 -0400
X-Newsreader: Microsoft Outlook Express 6.00.2600.0000
Organization: TDC Internet
When browsing datasheets for resistors I'm allways a litte confused as to
the validity of the specification stated. I wonder if you could help me out
with these simple and somewhat embarrasing questions:
A standard 0805 SMD 1% resistor is chosen (datasheet:
OK - so the maximum deviation at the production line is 1%, thats fine - but
what I'm curious off is the spread of production of the PCB and drift
I would normally just use the 1% spread and calculate the drift coming from
the temperature coefficient. But is this enough - several other factors are
described in the datasheet:
Shelf life, short term overload, climatic, rapid temperature change,
soldering and vibration.
My question is which of these factors will make permanent changes to the
Also the "Temperature rapid change" isn't that a bit dubious - rapid is
pretty relative? (from person to person)
And finally what would you guys from experience use for your worst
case/drift calculations? - load, soldering and vibration - or all of them?
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup