Re: To JT : non T analog switches?


"Joerg" <notthisjoergsch@xxxxxxxxxxxxxxxxxxxxx> a écrit dans le message de
news:uPUvf.42876$dO2.20815@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> Hello Win,
> >
> > A few things on those datasheets. One, the NLAS4501 says SPDT, but
it's
> > clearly an SPST switch! (Use an NLAS1053 or NLAS4053 for SPDT.)
Second,
> > the NLAS323 data*** says "Ultra Low < 5 pC Charge Injection," but
hey,
> > that's not even low, let alone Ultra-low! Sheesh! Those are cute
parts,
> > but go to Analog Devices for low and ultra-low charge injection, below
1pC.
> >
>
> Or use quad diodes.
>

Sorry Joerg, but I didn't give all the story.
pA level leakage, low charge, but also few 10s of nV level thermal recovery,
high isolation on high impedance and low noise. I'm afraid a diode bridge
won't do.

This is for a sample&hold or more precisely a block and pass switch (don't
know how to call that better) which will be ahead of my low noise
preamplifier and will allow the DUT transient recovery analysis without
suffering from the low noise preamplifier recovery. (few 10s nV accuracy
after a 0.5V transient).

But I'm now more carefully looking at some AD parts I discarded before and a
(very) few look promising.


--
Thanks,
Fred.


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