From: Joerg Hansmann (info_at_jhansmann.de)
Date: 2002-01-09 00:09:49
Hi,
----- Original Message -----
From: sleeper75se <sleeper75se_at_yahoo.se>
To: <buildcheapeeg_at_yahoogroups.com>
Sent: Tuesday, January 08, 2002 2:29 PM
Subject: [buildcheapeeg] Re: Input protection
...
> One question about those FET-diodes... they are only connected to V+.
> Shouldn't there be diodes to V- as well?
I am confused about this detail too.
The gate-source breakdown voltage for Ig=1uA is -35 to -40 V minimum for
the 2N4393 (Temic/siliconix datasheet). This is from the absolute
maximum ratings and I am not sure if the breakdown is reversible
like in z-diodes.
If it were z-diode like, it would not be useful anyway, because the
internal clamping diodes to v- (see block diagram) would conduct long before
the gate-source breakdown occurs.
> Of course, the people at
> Linear know what they are doing...
Do not be too credulous. To err is human.
In case of doubt an email to Linear Technology will help.
Regards,
Joerg
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