[sdiy] CA3086 and CA3046?

[patchell]

    Man, I am so stressed out at the moment, I can't remember if I replied to this or
not, so....here goes anyway...

Christian wrote:

> On Thu, 16 Aug 2001 12:37:53 -0700, you wrote:
>
> >> Another question. Anyone doing anything fancy with Pin 13 (substrate)?
> >> I am currently tying all spare transistor bases and emitters to ground
> >> (which includes that pin).
>
> >    Pin 13 MUST go to the lowest DC potential that any of the pins on the CA3046
> >will see.  The transistors are isolated with basically a reversed biased diode
> >junction.  You also have to remember that the breakdown voltage of this part is
> >only 20 volts, so choose wisely, although, I have stretched this and have run
> >them at 27.5 volts.  What I really need to do myself is set up a little rig to
> >test the breakdown voltage....
>
> The lowest DC potential in my circuit is the -15V supply rail. I am
> unsure if the transistor pair I am using will ever see this, but I
> might as well tie the substrate line to that rail just in case. Yes?
>

    Yes, this is the sure fire way.  The best way, is, to find out what the lowest
voltage will be, but, I have to confess, I am usually way to lazy and just use the
-15V myself.  The thing you need to remember is that 20 volt limit...

>
> Many thanks for your help BTW.
>
> Christian.

--
 -Jim
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