Hi,

I4m looking to build a S/H stage to be driven with a 16X84.
I know of the Analog switch 406?, but I think this sould be able to
be done also with a single FET.

Signal to be switched is approx 0..14V.

Goal is, to suppress (switch stage to hold) during a known time
where noise occures. the signal therafter is feed into a integrator and
a comperator
which4s output will be read by the PIC.

what kind of Fet should I use - can you suggest a type-name.

One of my problems with this is the knowledge, that the voltage between
gate
and source should not be to large( to keep the fet alive). Also, when
the fet is switched on, the potential of the source may be at e.g. 8V -
When thinking of a bc547 the basis has to be controled with a voltage
more positive respective the emitter.

I heard about "logic" Fets with ability to be drive by logic. while I
assume that
with source grounded, they behave like a npn transistor - how do they
act if
source is above the logic-high ??

Also I4m somewhat in trouble with "enhancment" and  "depletion" mode.
What type
to use in what certain case ? Are there any good avaliable "joe-user"
type models ?

Kind regards

        Stefan