Custom Power Inductor

Inductance

DC current

• Saturation knee — inductance has fallen ~20% from its small-signal value. Size the part so your peak current sits left of here, not at the rated figure.

• Two currents get quoted and they are not the same: the thermal rating is what the winding can carry continuously, the saturation rating is where the core gives up. The lower of the two is your real limit.
• Ripple rides on top of the DC bias, so check the peak of the ripple against the knee — not the average.
• Saturation moves with temperature. A part sized at the knee on the bench can be past it in a hot enclosure.