Op-amp supply voltage vs noise

[ricko_uk]

Hi,
in a dual-supply op-amp design, does the supply voltage in any way affect the noise?

Does higher voltage increase noise, decrease it or does not affect it at all?

Thank you

[Kleinstein]

There can be a small effect of the supply on the noise. Which way and how much depends on the OP type. It can be either way and normally the effect is rather small, especially with newer types. Some older type may have a not so stable current biasing and this way can have a decreasing noise with increasing supply current when the supply goes up.

Higher voltage can increase the 1/f noise in JFETs, so a higher voltage can also be bad.

[David Hess]

in a dual-supply op-amp design, does the supply voltage in any way affect the noise?

Does higher voltage increase noise, decrease it or does not affect it at all?

With some exceptions, the effect of supply voltage on noise is insignificant unless it changes the operating point of the circuit.

Dual supply circuits which use tracking so that noise is mirrored between the supplies do not have to rely on common mode rejection to reject noise as much, and tracking supplies are sometimes used for exactly this reason in the lowest noise applications.  So there is some benefit especially when common mode rejection is limited.