ADA4528 datasheet says that the input voltage offset has a TEMPCO of 0,015uV/°C.
How TEMPCO is measured? Is the temperature rate of change relevant?
I developed an amplifier, based on ADA4528, that exhibits higher offset voltage than expected. I know that a bad dimensioning (bad resistor choice for example) can affect the device performance. Unfortunately I cannot make my circuit public so I cannot post a picture here.
I simulated the circuit, using the ADA4528 spice model, and found a quite lower offset voltage. The simulated value is in accordance with the one I calculated.