[sdiy] Decoupling caps?

[charlie lamm]

Great suggestion!

To keep things as "bargain basement" as possible, I guess I will try to
shove the bypass caps in there first.  If I have no room, I will go to
Marvin's suggestion.

But there is an issue.....

Using Eagle PCB, which sounds like the software of choice for this
group.....I can't figure out how to adjust the schematic so the
caps "show up" for the TL082's.  There are power pins visible for the
LM311 and the CA3140 in the linear library, so that's easy, just add them
between these pins and ground then flip to the board and trace 'em
up...assuming of course I can make room for them.....

Not for the TL082's, all that I get are the + and - inputs and output for
each of the 2 stages, no power pins.  Is it necessary to monkey around
with the library (export + edit + import?)  or do I just add them to the
schematic as unconnected to the IC's and then wire them up only on the
board?


On Fri, 10 Jan 2003 Marvin.Jones at nokia.com wrote:

> No one has mentioned the sockets which have an integral decoupling cap built right into the socket.  Mouser carries the Mill-Max versions.  I'm sure Amp and others do them as well.  They are a bit more expensive, but a great way to save the space of the decoupling caps on a tight layout.
>
> mj
>
>
>
> > -----Original Message-----
> > From: ext charlie lamm [mailto:charlie at www2.charlielamm.com]
> > Sent: 10 January, 2003 09:36 AM
> > To: synth-diy at dropmix.xs4all.nl
> > Subject: [sdiy] Decoupling caps?
> >
> >
> > I have read often that when setting up PCB's one
> > should always use decoupling caps (.1uF or so) for
> > IC power pins.
> >
> > I am designing a PCB for the ASM-1 VCO.  I am limited
> > in board space and want to make a single sided board so
> > I can press-n-peel.
> >
> > Now, I know this may be too general a question, maybe too
> > general, but,
> > how important are the decoupling caps in a circuit like this?
> >
> > I assume decoupling would be extremely important in OTA's,
> > since they seem to react badly to poorly regulated supplies....
> > but with TL082's etc?  Can I get away with not using them
> > and still have the VCO sound decent (in tune/not too badly
> > distorted or
> > noisy).
> >
> > Maybe I can put some decoupling caps away (bigger? 10uF?)
> > from the IC's
> > where there is a bit more room on the board?
> >
> > Or should I just tweak the design to figure a way to fit these in?
> >
> >
> >
>