From: Winfield Hill
Subject: Re: ground loops, optoisolators, and ADC noise, oh my!
Date: 21 Jan 2003 15:53:43 -0800
Organization: Rowland Institute
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Roy McCammon firstname.lastname@example.org wrote...
> Winfield Hill wrote:
>> email@example.com wrote...
>>> I've been looking at optoisolators but they're expensive and slow.
>>> Plus, they all show propagation times that don't seem that suitable --
>>> they vary markedly with temperature and input current, all of which
>>> would contribute (50-100 nS in some cases) of jitter to the CONVST.
>> Opto-isolators aren't all THAT slow...
> NACK NACK NACK
> Those dang thangs are optocouplers.
> They couple signals from input to output using optics.
> Their primary function is coupling.
> If the primary function was isolating, we'd just so an open circuit.
> SYSTEM CRASH. WARNING WARNING. SAVE FILES NOW. xkdoi
Thanks Roy! I've always used the terms interchangeably, and I
suppose many of us do. We used both terms in our book. However
a quick examination of some manufacturer's literature shows that
you're correct, the widely used term is optocoupler. Siemens in
their databooks say "optocoupler (opto-isolators)." That's their
solution, but none of the others I examined use the term at all.
One company uses neither term, calling them solid-state switches,
even if they're made from BJT photo-transistors. :>)