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

[Harry Bissell Jr]

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
> > >
> >
> 
>