AVR-Chat

Steve -

I would hardly call it paranoia. That is exactly how I would interpret it.

One thing to watch out for with lower leakage devices. The spread between
the hold-off voltage (working voltage) and the breakdown voltage MAY be
greater which could translate into a larger series resistor between the
transient protector and the micro. Not saying that this IS the case, just
check it before running down that path. Also check device capacitances.
Easy to overlook.

Jim

> Jim, a quick question.  It's probably a dumb one, but I'm getting a bit
> paranoid that I could be missing something.  I assume the leakage current
> only occurs when the line is high, or more correctly, above ground
> (ignoring
> transient events).  If so any active-low line that is pulled high when not
> asserted (say using the internal pull-up in the uC) would be incurring
> this
> leakage current when "idle".  Is that correct?
>
> The Transguard series has a pretty high leakage current, 100 uA.  So with,
> say, 50 lines pulled high, all with a Transguard, this adds up to 5 mA,
> way
> more than what the AVR itself will consume on average!   It's beginning to
> look like another "gotcha" to me and I should really switch to lower
> leakage
> current ones like the Staticguards at 10 uA.
>
> Thanks, Steve
>
> | -----Original Message-----
> | From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On
> | Behalf Of Jim Wagner
> | Sent: Saturday, January 08, 2011 11:57 AM
> | To: AVR-Chat@yahoogroups.com
> | Subject: Re: [AVR-Chat] AVX Transguard
> |
> | Yes, that was the "I think" caveat. That suggests being able to use
> | smaller limiting resistors.
> |
> | The high capacitance CAN be a challenge. Sometimes, it will actually
>
>
> __________ Information from ESET Smart Security, version of virus
> signature
> database 5775 (20110110) __________
>
> The message was checked by ESET Smart Security.
>
> http://www.eset.com
>
>
>