2.2 µH, 500 mA — DC-DC filtering fit
The LQH43NN2R2M03L is a 2.2 µH drum-core wirewound inductor from Murata's LQH43 series, rated for 500 mA continuous current with a maximum DC resistance of 300 mOhm. For a typical 3.3 V buck converter switching at 1 MHz, this inductance value and current rating suit output filtering for loads drawing up to about 400 mA after derating for core loss and ambient temperature. The 300 mOhm DCR at 500 mA produces a conduction loss of 75 mW — acceptable in most designs but worth stacking into the thermal budget if the inductor sits near other heat sources in a confined enclosure.
Unshielded drum core — placement discipline required
This is an unshielded ferrite-core inductor. The open magnetic field radiates into the surrounding PCB area; keep sensitive analog traces, RF nodes, and low-level sensor inputs at least 5 mm away, or shield the inductor with a grounded copper pour on the layer below. The self-resonant frequency of 62 MHz is well above the 1–2 MHz switching range of most point-of-load converters, so the inductor behaves as a pure inductance in that band. The Q factor of 20 at 1 MHz is moderate — adequate for power filtering but not for resonant tank circuits where a higher Q (above 50) is typically specified.
Temperature grade and operating envelope
The ferrite core's saturation current derates above 85°C; at 105°C ambient the effective current rating drops to roughly 70% of the 25°C value, so budget 350 mA as the practical ceiling in a hot enclosure.
1812 footprint — board integration
Tape-and-reel packaging supports automated pick-and-place. Tolerance is ±20% — typical for power-grade wirewound inductors in this value range. The inductance is tested at 1 MHz, which is the standard test frequency for this class of part.