building precision voltage reference from 0 to 3 volts

[tictac]

Hi
How can I build a precision voltage from 0 to 3 volts, that does not change with changing of ambient temperature and low noise?
For example with TL431 we can have precision voltage from 2.5 volts to upper voltages.
Regards

 

[Analog Ground]

Do you next fixed or adjustable? If fixed, start with a regular precision, low noise voltage reference, attenuate the output with precision, low temperature coefficient resistors and buffer with a low noise, low drift op amp. Could you give more detail of your requirements? More specs? How stable? How precise?

 

[tictac]

Hi
I want to have a variable voltage between 0 to 3 volts.
can I use tl431 for building fixed 3volts and finally change it with one pot? Is it precise?I think that I cant have a precise output voltage with pot. I want to give this variable voltage for adjusting current source that I describe about it on another Post in this forum.

 

[kam1787]

https://www.digikey.hk/Web Export/S.../Copal_CermetTrimmerGlossary.pdf?redirected=1

for wire-wound pots it's fine

 

[crutschow]

If you want a voltage accurately proportional to a dial setting, then you can use a 3-turn or 10-turn precision potentiometer with a 10-turn, 3 digit dial indicator (and buffer the pot output with a low offset op amp if a low output impedance is needed).

 

[Analog Ground]

A ten turn wire potentiometer will give a resolution and linearity approaching 0.1%. Remember to put a resistor in series with the potentiometer from the voltage reference to tune the adjustment range and give the maximum resolution for the required voltage range. Bourns is the company which makes good, precision potentiometers which are widely available.

https://www.bourns.com/ProductLine.aspx?name=precision_pots_multiturn

Another approach is a high resolution, digital-to-analog converter using the precision voltage source as a reference. A very high resolution can be obtained. This approach gives remote control but a more complex manual control is needed (for example, a microcontroller with keypad)..