Original question:
Dears
we have used the OPA2376 in a high DC accuracy system, and we have found the DC offset over max spec limitation mentioned in datasheet, like 30uV , so need your help if this is normal or have some issue. we measured the offset with a 8 1/2 multi meter, so the measurement method is ok.
Our datasheet typical offset is around 5uV. So does the additional offset is from the soldering stress? or how we checked the offset spec in our bench?
Thanks
Jun Shen
Hi Jason,
Please send us the schematic and gain parameters as Kai suggested.
Please use the same parameter settings if you want to verify the Vos.
Your Vos circuit should be configured similar as follows: You should match the parameter settings as presented in the datasheet.
Best,
Raymond
Hi Michael,
I think that dVos/dT is likely uni-directional. For a given IC, the Vos will either go positive or negative in slope vs. temperature. dVos/dT will be positive in either cases.
Hi Shen Jun,
I think that the output resistor load is required, since you are comparing the Vos figure from the datasheet. Otherwise, it will be apple and orange comparisons.
Also, you need to make sure that V1, V2 and Vcc shall have an equal precision down to uV or better in accuracy or your measurement error will be large.
/cfs-file/__key/communityserver-discussions-components-files/14/OPA376-Input-Offset-Sim-08122020.TSC
Best,
Raymond
Well actually Raymond, it is more common to see bipolar drift limits as the slope could be either positive or negative going from cold to hot. It might just be different groups doing the parts, or is it actually the fact the 376 has a unipolar drift - I kind of doubt it.
And then here is the work we were doing on the OPA837, definitely bipolar slopes with some really odd outliers on the Ios drift.
