Im trying to create a +/- 2.5V supply from a +/-5V. I have a couple of 2.5V voltage references. Am I right in assuming that I need to get hold of a -2.5V reference? I did read an article that showed how I could use an inverter but I don't have any of those either.
There seems to be a gap in my knowledge because I don't really understand the difference between a voltage reference and a voltage regulator.
Thanks
G
If your 2.5 volt references are shunt type (two terminals that hold 2.5 volts when an externally limited current is passed through), you can use two of them to regulate a small (milliamperes) supply. If you want a more significant current from these supplies, you should use actual supply regulators. The adjustable LM317 and LM337 pair can be set to 2.5 volts output with a pair of resistors.
You need a low-impedance driver set at 2.5V relative to your current ground and this new low impedance driver needs to source or sink (two-quadrant, if my hobbyist knowledge of terms is close to right.)
You don't say what your _current_ requirements will be. There's a simple answer if you are talking about a few tens of mA. This is the TLE2426 "rail splitter." Also, an opamp set up with the 2.5V reference to its (+) input and its (-) tied to its output, which drives the new center point "ground" might be okay, assuming your opamp can deliver the current requirements you are looking for. (Or just use a resistor divider instead of the 2.5V reference, to the (-) input.) A discrete splitter could be formed out of transistors, too.
A reference usually has a very small _current_ drive capability -- not uncommonly in microamps -- to name one important difference.
Jon
Sorry, I meant (+), not (-).
Jon
use a 2425 and turn it around. the COM will be the - line and (IN) your common .
-- "I\'m never wrong, once i thought i was, but was mistaken" Real Programmers Do things like this. http://webpages.charter.net/jamie_5
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.