[sdiy] 2164 overvoltage condition?

[Roman Sowa]

http://www.milton.arachsys.com/nj71/index.php?menu=2&submenu=2&subsubmenu=3

Roman

W dniu 2017-06-27 o 06:49, Quincas Moreira pisze:
> Dave, you're a rock star :)
>
> Incidentally, I've heard there's a common trick with diodes done in most
> designs to protect the 2164 from frying by getting power on one rail
> before another (or something like that). Can somebody explain that
> better to me?
>
> On Mon, Jun 26, 2017 at 11:42 PM, David G Dixon <dixon at mail.ubc.ca
> <mailto:dixon at mail.ubc.ca>> wrote:
>
>     __
>     You should also realize that the 2164 is a current amp.  I know that
>     the datasheet says that the absolute maximum voltage of the input is
>     the rail voltage, but one never feeds a voltage source directly to
>     2164.  One drops the voltage across an input resistor (usual 30k)
>     because the input pin is at virtual ground.  Hence, assuming a +15V
>     supply, the largest current the input pin ever sees is about 500uA.
>     If the rail is connected directly to the input pin, who knows what
>     the input current is -- possibly enough to fry the chip, I guess.
>
>     ------------------------------------------------------------------------
>     *From:* Synth-diy [mailto:synth-diy-bounces at synth-diy.org
>     <mailto:synth-diy-bounces at synth-diy.org>] *On Behalf Of *Sean Ellis
>     *Sent:* Monday, June 26, 2017 6:48 PM
>     *To:* synth-diy at synth-diy.org <mailto:synth-diy at synth-diy.org>
>     *Subject:* [sdiy] 2164 overvoltage condition?
>
>         I've been breadboarding a filter and oscillator using a single
>         2164 and I think I just fried my only 2164 on hand. I have the
>         power supply protected but accidentally put -12 straight into
>         the input of one amp (the control pin was at about 2.5V) and
>         suddenly it died. The datasheet specifies the max ratings to the
>         supply rails so I don't get why it could have (seemingly)
>         destroyed the chip. Could it maybe have caused excessive heat?
>
>
>         -Sean
>
>
>     _______________________________________________
>     Synth-diy mailing list
>     Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
>     http://synth-diy.org/mailman/listinfo/synth-diy
>     <http://synth-diy.org/mailman/listinfo/synth-diy>
>
>
>
>
> --
> Quincas Moreira
> Test Pilot at VBrazil Modular
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at synth-diy.org
> http://synth-diy.org/mailman/listinfo/synth-diy
>