Long Term Offset Voltage Drift

Hi Krn, 

Long term offset drift isn't typically part of standard production testing since it requires extended aging to measure. May I ask why you need this data? 

Regards,
Ian

Hello Ian,

I am planning to use this on a highly accurate electrical instrument & interested to know what is the offset drift does the IC undergoes in 1 year. I notice that for productions parts like LTC2055, it is typically mentioned as 50nV / sqrt (month). 

Hello Ian, I am planning to use this on a highly accurate electrical instrument & interested to know what is the offset drift does the IC undergoes in 1 year. I notice that for productions parts like LTC2055, it is typically mentioned as 50nV / sqrt (month). Please can you comment long term drift of ADA4522-1.

Hi Krn, 

LTC2055 specifies long-term drift because its auto-zero architecture relies on periodic sampling and storage of the offset correction, which can introduce a very small statistical random-walk component over long periods. Similar long-term offset change can also be observed in older laser-trimmed architectures, which do not have dynamic offset correction and are therefore subject to device aging.

For chopper-stabilized op amps such as ADA4522, long term offset drift is not specified because the continuous chopping mechanism dynamically removes offset, including any offset introduced by aging, making long-term drift a non-meaningful error term for this architecture.

You may refer to this article for additional information:
MT-037: Op Amp Input Offset Voltage

Best Regards,
Ian

Hello Ian,

Thanks for your reply. For the chopper-stabilized opamps, I understood that auto-zero circuit removes any offset due to aging. Does the auto-zero circuit also removes the voltage offset & voltage offset's temp drift?