Hi,
A general question : we expect have similar input offset voltages on the 4 amplifiers in a quad package ?
Thanks,
No.
The two input transistors of a single opamp are placed near each other on the die so that they have as much the same characteristics as possible. This implies that any differences are caused by local changes on the die.
The input transistors must be near the input pins, so the inputs of different opamps are usually far apart. See, for example, the LM358:
(source: zeptobars.com/en/read/TI-LM358-dual-general-purpose-opamp)
This means that the input offsets of the two opamps on the same die are pretty much independent of each other.
For an opamp with resistor trimming or e-trim, the remaining offset depends on the accuracy of the trimming mechanism, which is independent of the die. The same principle applies to chopper opamps.
