I designed some analog second-order all-pass filter in LTspice and provided Monte Carlo analysis as well. I want to evaluate the obtained AC results with .meas command, particularly:
- Magnitude variation at pole frequency (.meas AC 'label' FIND mag(V(out)) AT 'freq value of interest') - this is done
- Pole frequency variation at -180°, which I would expect as '.meas AC 'label' FIND frequency AT ph(V(OUT))=-180', however it does not return anything. Could anybody help please?