What the 1.65 A rating means on a 3.3 µH part
The Murata LQH43CN3R3M33L is a drum core wirewound inductor in the LQH43 series, built on a ferrite core and unshielded. The headline numbers are 3.3 µH ±20% at 1 MHz test frequency, with a current rating of 1.65 A and a maximum DC resistance of 99 mOhm. That 1.65 A is the saturation or heating limit — whichever hits first — so in a buck converter feeding a 1 A load, this part runs with margin. The self-resonant frequency sits at 47 MHz, which tells you the useful band stops well before that; above SRF the inductor looks capacitive.
1812 footprint and what it connects to
The 1812 (4532 Metric) package is a standard SMD footprint — 4.50 mm x 3.20 mm, seated height 2.80 mm max. No shielding, so keep it away from sensitive analog traces or other magnetics on the same layer; the unshielded field couples into adjacent copper. The ferrite core handles the flux path, but the fringing field will induce eddy currents in a ground plane poured underneath — leave a keep-out zone under the body if the layout is tight.
Temperature range and field survival
If the board sits inside a vented enclosure near a 60°C ambient, the inductor's self-heating from the 1.65 A current plus the ambient stays under the 85°C ceiling as long as the DCR losses are within the datasheet curve. No AEC-Q grade here, so skip it for under-hood or engine-bay duty.