I/O pins protection
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Hi group,
A BS2 is receiving a signal from a PNA4613 (40Khz IR detector), there is
a
20 feets cable between both, I have a .1 uf capacitor from pin to ground
near
the BS2, is it enough? Should use a bigger one or add a zener? For now,
I can't
add an optocoupler.
Thank you
Rene
A BS2 is receiving a signal from a PNA4613 (40Khz IR detector), there is
a
20 feets cable between both, I have a .1 uf capacitor from pin to ground
near
the BS2, is it enough? Should use a bigger one or add a zener? For now,
I can't
add an optocoupler.
Thank you
Rene
Comments
> 20 feets cable between both, I have a .1 uf capacitor from pin to ground
> near the BS2, is it enough? Should use a bigger one or add a zener? For now,
> I can't add an optocoupler.
Is it working? If so then it probably doesn't need to be "fixed". ;-)
IMHO every (CMOS/TTL) chip ever made should have a .1 uF mylar capacitor
built in across it's power lines to ground. Once upon a time DEC made four
layer boards where all the signals were on the outside surfaces and the two
inside layers were power and ground. They were separated by a large maylar
sheet that acted like a big capacitor. Those boards never had a noise
problem on their power lines. ;-)
--
Enjoy,
George Warner,
Schizophrenic Optimization Scientists
Apple Developer Technical Support (DTS)
what are you trying to protect the BS2 of ?
* noise :: add capacitor as close possible to the Stamp. Also shild the
wire, and connect the shield only at one side.
* electrostatic :: add a couple of diodes close to the BS2, both connected
to the line. Anode 1 to Ground, and Catode 1 do line. Anode 2 to line, and
Catode 2 to VCC.
Regards
Antonio Sergio Sena
Antonio Sergio Sena
(Field Applications Engineer)
Primetec - Engenharia de Sistemas, Lda.
Rua Porto Alegre, 9 - 1º Esq.
2780-031 Oeiras
PORTUGAL
e-mail: asena@p...
WEB: www.primetec.pt
Original Message
From: "Rene Genest" <rene.genest@q...>
To: "stamp" <basicstamps@yahoogroups.com>
Sent: Thursday, April 08, 2004 9:55 PM
Subject: [noparse][[/noparse]basicstamps] I/O pins protection
> Hi group,
>
> A BS2 is receiving a signal from a PNA4613 (40Khz IR detector), there is
> a
> 20 feets cable between both, I have a .1 uf capacitor from pin to ground
> near
> the BS2, is it enough? Should use a bigger one or add a zener? For now,
> I can't
> add an optocoupler.
>
> Thank you
>
> Rene
>
>