From: RussellMc <apptechnz@gmail.com>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
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Date: Wed, 26 Feb 2020 15:42:32 -0800
Subject: Re: [EE] 74LVC1G332 input clamping current only specified for VI <
 0 V
Thread-Topic: [EE] 74LVC1G332 input clamping current only specified for VI <
 0 V
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On Thu, 27 Feb 2020 at 08:07, Jason White <whitewaterssoftwareinfo@gmail.co=
m>
wrote:

>
> I am considering subjecting the input of a 74LVC1G332 to 12 to 48V
> though a resistor and relying upon the internal clamping diodes.
>
>
Note: This is the latest in a decades long, often futile "lecture series"
on the same subject, with the same old message:


Apart from what others have noted re there being no upper clamping diode,
it is NEVER a good idea and variably often a bad or very bad idea to rely
on internal / body diodes to clamp externally applied voltages  in order to
maintain them within "safe" limits.

When a body diode conducts more than a few microamps (and occasionally
before that) it is an indication that a condition has occurred that the
spec sheet seeks to prevent.

Once current is injected into the substrate in an uncontrolled and
unspecified manner, "where it goes, nobody knows" and what the results are
range from invariably bad through sometimes bad to "I wonder why this
system occasionally does xxx" / "why did it die" / "why did it kill him".

YMMV


         Russell
--=20
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