18 µH wirewound inductor for general-purpose filtering and DC-DC smoothing
The Murata LQH43MN180J03L is a drum core wirewound inductor in the LQH43 series, offering 18 µH inductance with ±5% tolerance. It is rated for 340 mA continuous current and has a maximum DC resistance of 820 mOhm. The unshielded construction and ferrite core make it a straightforward choice for power supply filtering, DC-DC converter output smoothing, and general signal conditioning where magnetic coupling is not a concern.
Self-resonant frequency and Q factor define the usable band
With a self-resonant frequency of 17 MHz, the inductor behaves as an inductor well below that point; above it, parasitic capacitance dominates and the impedance drops. The Q factor of 35 at 1 MHz indicates moderate energy storage efficiency at that test frequency. The 820 mOhm DCR sets the I²R loss at 340 mA to about 95 mW — acceptable for most board-level applications, but worth checking against the thermal budget in a dense layout.