[TriEmbed] How to Damage an LDO

[Carl Nobile]

Brian,

Look at the circuit in the datasheet for the 7805 and see if it will cause
issues. The datasheet itself may also say if it will.

The alternative is to put a schottky diode is series with the regulator
preventing anything from getting back to the regulator. You could use a
1N4003 or other in that series, but a schottky diode will have less voltage
drop like a 1N5819.

~Carl


On Tue, Dec 8, 2015 at 5:36 PM, Brian via TriEmbed <triembed at triembed.org>
wrote:

> Hi,
>
> If a linear voltage regulator sees its nominal output voltage across its
> GND/OUT pins while its IN pin floats, is it going to be damaged?
>
> For example, a 7805 regulating a 9 volt battery, but the battery is
> disconnected and an AC adaptor is supplying 5 volts.
>
> This seems like a thing I should /just know/, but I can't figure out a
> good way to google for it, or to divine it from a datasheet.
>
>
>
> Thanks!
> -Brian (one of many)
>
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>



-- 
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Carl J. Nobile (Software Engineer)
carl.nobile at gmail.com
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