Attenuator AC 1Mohm overdrive of OPA859
Mismatch from simulation file to schematics.
In the simulation file of the input stage, OPA859 is AC-coupled to the input.
In the schematics, the input DC level is fed to OPA859 with attenuation 1:2, still too much due to the limited power rail voltage of OPA859. Is OPA859 robust against DC+AC level above power rails? DC level seems a bit protected by 25Mohm resistor, but with a fast AC signal superimposed could exceed the absolute voltage with low-impedance source.