Is it possible and reasonable to make a voltage reference that outputs 0.675V +- 0.005 over an input of 6 to 40 volts?
\$\begingroup\$
\$\endgroup\$
Add a comment
|
1 Answer
\$\begingroup\$
\$\endgroup\$
4
Yes.
.675V +/- 0.005V is +/- 0.7%.
Digikey lists a lot of voltage references at 0.5% or better regulation.
Once you choose a reference, you can adapt the input voltage (if necessary) with a preregulator, and you can adapt the output voltage (if necessary) with a resistor divider.
-
3\$\begingroup\$ That 0.5% is usually also initial accuracy. They're generally much better with regard to drift. You would just need to trim the output voltage once, when you first assemble the system. \$\endgroup\$ Commented Sep 9, 2013 at 22:55
-
2\$\begingroup\$ Someone should explain why accurate references are less favored over ones with controlled drift/tempco. Connor Wolf's comment deserves a separate answer \$\endgroup\$– HL-SDKCommented Sep 10, 2013 at 1:26
-
2\$\begingroup\$ I would like to see @ConnorWolf expand into a full answer as well. Trims have their own costs and drawbacks. If a spec can be fulfilled with fixed components of reasonable cost, that makes a better design. \$\endgroup\$ Commented Sep 10, 2013 at 3:20
-
\$\begingroup\$ @markrages - I certainly wouldn't argue that something you can do that doesn't involve manual trimming is a lot nicer from the assembly process. However, it tends to be more expensive.As usual, it's a matter of where your priorities are (accurate, easy, cheap - pick any two). \$\endgroup\$ Commented Sep 11, 2013 at 3:52