Op-Amp input offset voltage vs. time

[Kingcosmos]

I have a simple, but curious question about an op-amp specification:
input offset voltage vs. time. I see this specified as uV/mo. Is
this caused by general aging of the part; i.e., regardless of being
powered on or stored on a shelf?
Also, is it assinine to assume that the offset will drift in one
direction +/- 1.5 uV/mo (OP07 from ADI for example) from the day 1
(whatever that day is) until eternity?

 

[John Popelish]

I have a simple, but curious question about an op-amp specification:
input offset voltage vs. time. I see this specified as uV/mo. Is
this caused by general aging of the part; i.e., regardless of being
powered on or stored on a shelf?

It can wonder in either case, but you won't know what it is
doing till you power it up.

Also, is it assinine to assume that the offset will drift in one
direction +/- 1.5 uV/mo (OP07 from ADI for example) from the day 1
(whatever that day is) until eternity?

It is not safe to assume that it will steadily drift in one
direction. It will do a random walk. There is also a warm
up drift that is usually worse. This spec assumes operating
at a constant temperature.