Maker Pro
Maker Pro

5V to 5V precision voltage reference

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
Joined
Jan 21, 2010
Messages
25,505
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
223
Joined
Sep 26, 2009
Messages
223
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
9
Joined
Oct 9, 2010
Messages
9
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
Moderator
Jan 21, 2010
25,505
Joined
Jan 21, 2010
Messages
25,505
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.
 
Top