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5V to 5V precision voltage reference

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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Doubtful.

The non-precision 5V source could fall to (say) 4.9V -- how do you get 5V from that?

OK, you could have (say) a switched capacitor voltage doubler followed by a precision regulator, but I don't know of any package that includes both of these.
 

barathbushan

Sep 26, 2009
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what do you mean by 'precision' ???
if you use standard regulators like 78xx , you probably need 2 volts to drop at the IC
so you have to supply 7v i/p .

But there is a another regulator that works with around 0.5 v drop out voltage , and if you draw less current the drop voltage may be even lesser [minimum 100mv]
just google out "LM2940" and check out its datasheet .
 

prescott2006

Oct 9, 2010
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what do you mean by 'precision' ???
if you use standard regulators like 78xx , you probably need 2 volts to drop at the IC
so you have to supply 7v i/p .

But there is a another regulator that works with around 0.5 v drop out voltage , and if you draw less current the drop voltage may be even lesser [minimum 100mv]
just google out "LM2940" and check out its datasheet .

In my project, I wish to get a precision 5V from a USB supply. Any way to achieve it?
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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Define "precision".

Then tell us how the 5V over USB is imprecise.

The easiest option is to get a switched capacitor voltage doubler and then follow that with a precision voltage reference (which is essentially a fancy regulator).

It might help if you tell us what you need the 5V reference for, and what current you'll require from it.
 
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