Hi, just thought I would share these results. I've tried to benchmark F30x opamp voltage and current noise density using F3Discovery with an external feedback network connected to a Tektronics MSO4054 oscilloscope. By changing the feedback network the current and voltage noise density can be found. Unfortunately the measurement is challenging. I wouldn't trust the results at higher frequencies, and the ~100nV/sqrt(Hz) "floor" is approaching the limit of my scope sensitivity. (But I've attempted to remove the scope noise floor from the results).