680 µH unshielded wirewound — DC-DC filter or low-current choke
This Murata LQH43NN681J03L is a ferrite-core drum wirewound inductor in the 1812 footprint, delivering 680 µH ±5% at 1 kHz test frequency. The 65 mA current rating and 17 Ohm max DCR set the practical ceiling — it is sized for signal-line filtering or low-power DC-DC output chokes where series resistance matters for efficiency, not for bulk power delivery. Q factor of 40 at 796 kHz and a self-resonant frequency of 2.5 MHz mean the inductance stays flat well into the hundreds of kHz range, rolling off above 2.5 MHz where the parasitic capacitance starts to dominate. For a buck converter switching at 500 kHz or a common-mode filter on a CAN bus, this part holds its value through the frequency band of interest. Surface-mount 1812 (4532 metric) package, unshielded — the open magnetic path means the inductor radiates flux, so keep sensitive traces or other magnetics at least one part-width away on the layout.
Sourcing — active, no cross-reference on record
This is a standard-production part in the LQH43 series, available through authorized and independent distribution. No official second-source or pin-compatible alternative is documented; the 1812 footprint and 680 µH ±5% tolerance are the fit criteria for a BOM replacement. Supplied on Tape & Reel or Cut Tape — reel quantity is the standard procurement unit for high-volume builds; Cut Tape works for prototypes or low-volume runs. Compliance documentation (RoHS, REACH) is available from Murata on request.