> While on the Pericom website, I stumbled across an 
> excellent
> EMI Appnote (#11) that states categorically:
>
> "If there are OpAmps in a design, terminate unused opamps 
> in dual
> or quad packs by grounding the positive input to ground, 
> then connecting
> the negative input to the output."

That is an excellent method.
Amplifier becomes a follower and has a defined input.

For a dual rail system around ground that's about as good as 
you'd get.

Only issue MIGHT be if amp was single supply & non rail-rail 
and had some issues, probably minor with out of range 
output. Odds are it would seldom be a real problem. I'd 
suspect that slightly better may then be using a signal-less 
input at enough above ground to get the amp in operating 
range. This could be a resistive divider across supply 
(reconstituted pseudo ground) or any local voltage that was 
essentially invariant.



        Russell 

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