Original question:
Tool/software:
Hello,
Mochi,
The original intent of the offset trim pins on op amps was to use a potentiometer to adjust the Vos to a minimal value. At the time this feature was popular most op amps had offset in the millivolt range, and trim could be used to reduce Vos from millivolts to hundreds of microvolts (10x improvement). Many modern op amps have offsets in the hundreds of microvolts or even single microvolt levels, so the offset trim pins were not added to these devices. The OPA627 has a worst case offset of 125uV and a typical of 25uV, so the decision was made to eliminate that feature. Some customers use the offset trim pins for a different purpose other than minimizing offset, so eliminating the trim in this case can cause issues for their application. In your case, are us just trying to minimize offset? If so, I think you could just rely upon the good offset and don't use the trim. If 125uV is not sufficiently low, there are other pin-for-pin op amps that don't have the trim pins but do have even lower offset. We can look for a lower offset device if that is your goal. There are a few (very few) devices that still have the trim pins. If your applicant uses the trim pins for something other than minimizing offset we can look for an alternative. However, in this case I doubt we will find an option that has the excellent specifications of the OPA627. Any devices that still have these pins would likely be general purpose devices with more relaxed specifications. A final option would be to do a PCB change to update the op amp circuit topology. Below is an image that shows how this can be done.
I hope that information helps.
Best regards, Art
