[sdiy] CA3280 sources -- Re: CA3080 - what to do?

[James Patchell]

In addition to what Harry said....there are some applications that each 
part really do things that the other can't.  One good example, the CA3280 
can make a really nice Tri-Sine converter because it has some features that 
the others don't have (access to the emitters of the differential pair).

Also, I like to use the LM13700 as a gain control element for temperature 
compensating VCO expo converters...either part will do this, but the 
LM13700 is much more cost effective.  Both parts are important (CA3280 and 
the LM13700).


At 11:23 AM 8/16/2004 -0700, Harry Bissell Jr wrote:
>The LM13700 (13600) has pretty crappy offset
>voltage variation with Gm bias.  The 3080 is
>usually better.
>
>The 3280 is most excellently better. At $4 it
>ought to be. And it is.
>
>The 3280 diode linearization scheme is a lot
>better than the LM13600/13700
>
>I would use the 3280 in any offset critical apps
>like attenuating a control voltage, etc.  If you
>can stand a little slop, the LM13600/700 is OK.
>
>H^) harry
>
>
>
>
>--- Ray Wilson <raywilson at comcast.net> wrote:
>
> > Hi All
> >
> > This is regarding the fervor to find 3080's and
> > 3280's. Beside the situation
> > where you need to replace a chip in a piece of
> > existing equipment, what
> > advantages do these chips have over the readily
> > available LM13700 in new
> > designs. No flames please I'm really just curious.
> >
> > Ray
> >
> > ----- Original Message -----
> > From: "john mahoney" <jmahoney at gate.net>
> > To: <synth-diy at dropmix.xs4all.nl>
> > Sent: Monday, August 16, 2004 10:00 AM
> > Subject: [sdiy] CA3280 sources -- Re: CA3080 - what
> > to do?
> >
> >
> > > As Don knows, I've recently gone 3280 hunting.
> > Sources for the CA3280 are
> > > fairly limited -- Intersil lists only Arrow and
> > Avnet. You won't find them
> > > listed at Mouser, Jameco, or Digikey, and forget
> > about the surplus
> > vendors.
> > > Here's what I found:
> > >
> > > Arrow lists them for $4.03 each, but with a 6 week
> > lead time.
> > > http://www.arrow.com/
> > > Avnet sells them for $3.636, but the minimum order
> > quantity is 500.
> > > http://www.em.avnet.com/
> > > Newark sells them, but see below.
> > >
> > > The best sources are:
> > > Small Bear Electronics, at $3.95 each.
> > http://www.smallbearelec.com
> > > And finally, Jim Patchell is (was) letting some go
> > for $4 each, "which is
> > > better than the 100 piece price from Newark." I'll
> > bet his shipping &
> > > handling fee is less than Small Bear's. ;-)
> > > --
> > > john
> > >
> > >
> > > ----- Original Message -----
> > > From: "Don Tillman" <don at till.com>
> > > To: "Fredrik Carlqvist" <ifrc at iar.se>
> > > Cc: <synth-diy at dropmix.xs4all.nl>
> > > Sent: Monday, August 16, 2004 11:26 AM
> > > Subject: Re: [sdiy] CA3080 - what to do?
> > >
> > >
> > > >    > From: "Fredrik Carlqvist" <ifrc at iar.se>
> > > >    > Date: Mon, 16 Aug 2004 10:32:53 +0200
> > > >    >
> > > >    > I use a lot of CA3080. It is my favorite
> > OTA. Now I hear Intersil
> > > >    > will cancel them. Are there any other
> > producers of CA3080 or
> > > >    > similar OTA's out there? Or should I now
> > buy 1000 CA3080?
> > > >
> > > > Use a CA3280.  It's a much better chip, it has a
> > great distortion
> > > > compensation circuit, it has a nice noise spec
> > (while the CA3080 has
> > > > no noise spec), and it comes in pairs.
> > > >
> > > >   -- Don
> > > >
> > > > --
> > > > Don Tillman
> > > > Palo Alto, California
> > > > don at till.com
> > > > http://www.till.com
> > > >
> > >
> >
> >

         -Jim
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