1.8 mH wirewound for low-frequency filtering
The Murata LQH43NN182J03L is a drum-core wirewound inductor with 1.8 mH inductance at 1 kHz test frequency — a high-value part suited for DC line filtering, LC tank circuits, or noise suppression in audio and low-frequency power rails. Rated for 35 mA continuous current with a maximum DC resistance of 45 Ohm — the DCR is the thermal bottleneck; at full rated current the internal power dissipation is roughly 55 mW, which is manageable in the 1812 footprint but leaves no headroom for ripple current.
Q factor and self-resonant ceiling
Q factor is 40 at 252 kHz — this is a moderate Q for a wirewound of this inductance; the inductor is usable in resonant circuits up to about 500 kHz before the Q rolls off significantly. Self-resonant frequency is 1.5 MHz — above this point the inductor behaves as a capacitor, so the part is not useful as an inductor above roughly 1 MHz.
Package, footprint, and temperature range
The ferrite core is unshielded, so magnetic coupling to adjacent components is possible; keep a 2–3 mm keep-out zone around the part on the PCB layout.
Sourcing and lifecycle posture
The base product number LQH43NN covers a family of 1812 wirewound inductors with different inductance values — if the BOM calls for a different value, the same footprint and package apply.