470 µH shielded inductor for automotive DC-DC filter stages
The Coilcraft LPS4018-474MRC is a 470 µH drum-core shielded inductor rated for 150 mA continuous current with a saturation floor of 140 mA — the 10 mA headroom between rated and saturation current means the core does not saturate before the winding reaches its thermal limit, a design margin that matters in automotive power-stage filters where load transients can push current above the steady-state rating.
7.8 Ohm DCR and 4.5 MHz SRF — the parametric trade-offs
The 7.8 Ohm maximum DC resistance sets the I²R conduction loss at 150 mA to roughly 175 mW — this is the self-heating floor inside the 1.8 mm seated height, so the thermal rise stays within the ferrite core's Curie temperature margin even in a dense surface-mount layout without forced airflow. A self-resonant frequency of 4.5 MHz defines the upper band edge where the inductor's parasitic winding capacitance cancels the inductive reactance — above this frequency the component behaves as a capacitor, so the 470 µH value is only valid for switching frequencies well below 4.5 MHz, typically in the 100 kHz to 1 MHz range for automotive buck or boost converters.