Other Parts Discussed in Thread: OPA4310, OPA4991, OPA2837
Hello,
do we have an any data of the offset matching of the 4 OpAmps?
Regards, Holger
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Hi Holger,
there's usually no correlation between the input offset voltages of the individual OPAmps in a quad OPAmp. The input offset voltages are totally random.
Kai
Offset is so random, that I used effect to solve two problems.
1) I had 50 post stress quad op amps (not sorted or serialized) and 50 prestress data logs. On one device, one channel changed, using offset voltage from 3 good channels, I was able to determine which data log matched this unit. So I could calculate the amount of change on 4th amp.
2) I had 12 dual op amps (serialization illegible) and 12 data logs. I was able to put all devices in same order as data logs.
Hello Holger,
Although not matching data, which Ron and Kai have both pointed out is random across the different channels.
The customer may always leverage the offset voltage specifications within the datasheet:
I have highlighted the typical value for the OPA4314:
Depending on the application's need, the op amp may be replaced with a different op amp that has a lower offset voltage.
I recommend either the OPA4991 or OPA4310.
All the best,
Carolina
One more data point, at one time I was working with test development to impose tested channel mismatch specs on the dual OPA2837. The data was showing a tighter matching than absolute with enough outliers to scare the yield people. So apparently, a spec survived, but actually broader than the single channel spec? Probably a no yield loss mandate on that test line,
Here is the single channel offset spec for the OPA2837
And then a single line of mismatch that widens this out, usually the typ number is the sigma of the distribution.