**Part Number:** OPA827

Hello,

I have some questions about the Vos drift over temperature.

In the initial description, I have found that typical value is 0.5uV/°C:

but in the following table, typical value becomes 0.1uV/°C:

Why are they different?

I have usually found zero mean Gaussian distribution in other OpAmp datasheets, but this is not the case. Looking at distribution of fig.7, it seems to be like a Gaussian distribution with a mean different from zero:

Pheraphs, is the 0.5uV/°C considered as mean and the 0.1uV/°C value as the standard deviation?

But if that's the case, why is 0.1uV/°C value only taken into account in the following example (an extract from precision labs 2.1 solutions) using the same OPA827?

In case of distribution with mean different from zero,as in fig.7, I would expect total Vos variation over temperature to depend on both mean and standard deviation (and not only on standard deviation):

+/- Vos(@25°C) **plus** +/- (mean value of Vos drift over temperature * deltaT) **plus** +/- (standard deviation of Vos drift over temperature * deltaT)

That comes back to the common form:

+/- Vos(@25°C) **plus ** +/- (standard deviation of Vos drift over temperature * deltaT)

in case of mean equal to zero.

I apologize for the lenghty email, but I would like to build a solid background in this matter.

Thanks and best regards,

Massimo