180 µH wirewound — the inductance and the current ceiling
The LQH32MN181J23L is a 180 µH drum core wirewound inductor from Murata's LQH32 series, rated for 65 mA continuous current with a maximum DC resistance of 10.2 Ohm. The 10.2 Ohm DCR is the dominant loss term.
Unshielded ferrite core — where the field goes
This is an unshielded drum core on a ferrite base. The magnetic field radiates freely from the winding — no magnetic shield can to contain it. In a dense board layout, keep sensitive analog traces, high-impedance nodes, or adjacent inductors at least a few millimeters away to avoid coupling. The ferrite core gives high inductance per turn but saturates at a lower current than an air-core or powdered-iron part of the same size. The self-resonant frequency is 6 MHz. Above that frequency the inductor behaves capacitively — the inter-winding capacitance dominates and the impedance drops. For a 100 kHz or 1 MHz switching regulator, 6 MHz leaves plenty of margin; for a 10 MHz DC-DC or a filter above 3 MHz, the usable bandwidth is narrowing. Q factor is 40 at 796 kHz, which is a moderate figure for a ferrite-core wirewound at that frequency. It means the inductive reactance is 40 times the effective series resistance at 796 kHz — acceptable for general-purpose filtering but not a high-Q tuned circuit where you need a sharp resonance peak.
1210 SMD footprint — board-fit reality
The nonstandard case designation means the pad layout follows the 1210 industry standard — 3.2 mm x 2.5 mm with the usual 1.0 mm pad width and 1.5 mm pad length. It reflows with standard lead-free profiles and fits pick-and-place without special handling. Operating temperature range is -40°C to 85°C, covering industrial and commercial environments but not automotive under-hood or extended high-temp applications. The ferrite core material and the epoxy coating hold up through the full range without significant inductance drift — expect about 5-10% drop at 85°C versus room temperature.
Lifecycle and supply posture
Sourced to order against BOM quantities. The part ships in tape-and-reel packaging (Cut Tape also available for prototyping).