100 µH shielded power inductor for automotive and industrial DC-DC stages
The Coilcraft LPS4018-104MRC is a 100 µH shielded drum core inductor in the LPS4018 series, rated for 350 mA continuous current with a saturation current floor of 340 mA. The 1.4 Ohm maximum DCR sets the DC conduction loss — at full rated current the I²R loss is roughly 0.17 W, which the 3.9 mm × 3.9 mm × 1.8 mm package must dissipate into the board copper.
Shielded construction and self-resonant frequency
The ferrite-core shielded construction contains the magnetic flux within the inductor body, reducing radiated EMI that would otherwise couple into adjacent traces or sensitive analog stages on the same board. This matters in a compact 3.9 mm footprint where the inductor sits close to the switching node of a buck converter. Self-resonant frequency is 10 MHz — above that point the inductor behaves capacitively and loses its inductive impedance. For a typical 500 kHz to 2 MHz switching regulator, the 10 MHz SRF provides adequate margin; the inductance remains flat across the switching band. Inductance is tested at 100 kHz, the standard frequency for power inductor characterization. The ±20% tolerance is typical for ferrite-core power inductors; the actual value at the operating current will shift downward as the core approaches saturation, so the 340 mA Isat is the hard ceiling for the DC bias.
Active production and sourcing posture
The part is not single-sourced — Coilcraft maintains multiple manufacturing sites for the LPS4018 series.