18 µH drum core for DC-DC filtering and signal conditioning
The Murata LQH32MN180K23L is a wirewound drum core inductor in the LQH32 series, delivering 18 µH ±10% inductance in a compact 1210 (3225 metric) surface-mount package. It is rated for 165 mA continuous current with a maximum DC resistance of 2.5 Ohm — the DCR sets the I²R conduction loss, so at full rated current the self-heating adds roughly 68 mW, which is manageable in most low-power DC-DC input filters and signal-line chokes.
Unshielded construction and self-resonant frequency
This is an unshielded inductor with a self-resonant frequency of 15 MHz — above that frequency the component behaves capacitively, so it is best suited for switching regulators and filters operating below 5 MHz where the inductive impedance dominates. The ferrite core material gives a Q factor of 35 at 1 MHz, meaning the inductive reactance is 35 times the effective series resistance at that test frequency — a reasonable figure for a general-purpose power inductor in this footprint.