Odp: [sdiy] 1/8th inch questions

[John Blacet]

I believe that this refers to the practice of including the output
resistor (1K) in the feedback loop of the op amp. For example, if you
have a 100K feedback R and a 1K output R, the actual output is taken
from the junction of the two, not the output pin of the amp. Of course,
this changes the actual gain, so you have to figure the Rs for that. I'm
not sure if this is something you can do with a buffer configuration.

In practice, we have opted to use a 100 ohm resistor for the output. The
074X series for example, is rated for indefinite short circuits to the
supplies and ground. The 100 ohm is just extra current limiting, but
gives us 10X the "fanout" of the 1K typically used.

--
Regards,
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John Blacet
Blacet Research
http://www.blacet.com