This circuit shows the "current channel" of an energy meter.
IA_IN are the two inputs for a shunt (typically 250 uOhms) while TP1 is the connection to the energy measurement IC, which uses the 3.3 V supply voltage (V3P3) as a reference.
The input uses ferrite beads as a form of filter for the incoming AC signal. I want to know what the effect of saturation will be on the ferrite bead inductors at the input.
Two primary things happen when saturated: 1) the effective permeability drops so the relationship between amp x turns and the field is no longer linear 2) you get "field popping" which describes the fact that the core can not longer contain the field and moves outside of the core. You van get very high EMI/RFI in these situation because of the huge disparity in in relative permeability. The field has to rapidly expand (outside of the core) to compensate.
In the case of the ferrite beads, you will lose filtering but in the circuit above only displacement current flows (because of C6 and C12) so only very extreme spikes will cause any saturation.
