• Resolved

Are input offset voltage and offset voltage temprature drift of an opamp correlated?

Let's say I know the polarity of the offset voltage from that information can I infer the polarity of the offset voltage temprature drift? For example, let's say non-inverting input is more positive than the inverting input. In that case is it safe to assume that the offset is going to increase towards the non-inverting input as the temprature increases or are they completely unrelated? Is input type of an opamp has anything to do with that?

  • Alperen,

    The temperature drift will be constant over the operating range of the OpAmp.  For example, in the LPV511 datasheet (www.ti.com/lit/ds/symlink/lpv511.pdf ) the following footnote on temperature drift: (4) Offset voltage drift is specified by design and/or characterization and is not tested in production. Offset voltage drift is determined by dividing the change in VOS at temperature extremes into the total temperature change.

    Also note there is considerable information in the BLOGS:  https://e2e.ti.com/blogs_/b/precisionhub/ ,

    as well as The Signal e-book: A compendium of blog posts on op amp design topics.


  • Alperen,

    There is a correlation between offset voltage and drift. However offset and drift are based on the matching of many components summed together. In other words the relationship complex. If one mismatch (of components) is much larger than the others then it will dominate for higher correlation between offset and drift.

    For example, here is a scatter plot for LM2902 drift vs. VIO

    Ronald Michallick
    Linear Applications

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  • In reply to Ron Michallick:

    Thanks for your response. I thought there is a very simple relationship between them. Now I know that I have to be more cautious about this thanks to your answer. Thank you very much.