1 µH shielded power inductor for automotive and industrial DC-DC
The Coilcraft LPS4018-102NRC is a 1 µH shielded drum core inductor rated for 1.8 A continuous current with a saturation floor of 3.8 A — the margin between rated and saturation current gives headroom for transient spikes in point-of-load converters without hard saturation.
DCR and saturation — the two numbers that set the thermal budget
42 mOhm max DCR at 25°C means the I²R loss at 1.8 A is 136 mW — the ferrite core and copper winding share the heat, but the 1.80 mm seated height limits the surface area for convection, so the temperature rise above ambient is dominated by the DCR, not the core loss, at switching frequencies below 1 MHz. Saturation current is 3.8 A at the inductance drop point — above 1.8 A the inductance rolls off gradually (ferrite core, not powdered iron), so a 2.5 A peak in a buck converter still holds enough inductance to keep the ripple current within the output capacitor's ripple rating. Self-resonant frequency is 180 MHz — well above the 100 kHz test frequency, meaning the parasitic capacitance across the winding does not limit the usable bandwidth until the VHF band; for switching regulators switching at 500 kHz to 2 MHz, the inductor behaves as a pure inductive element.
Shielded construction and footprint for board-level EMI management
Shielded ferrite core contains the magnetic field within the 3.90 mm x 3.90 mm footprint — adjacent traces on the same layer see less flux coupling than an unshielded drum core, which matters when the inductor sits next to a sensitive analog signal chain or a high-impedance feedback node. Surface-mount package on a nonstandard footprint — the 3.90 mm square land pattern is smaller than the standard 4040 footprint, so the PCB layout must match the recommended pad geometry from the Coilcraft drawing to keep the solder fillet height consistent across reflow.