1.2 µH wirewound with AEC-Q200 qualification
The Murata LQH43NH1R2K03L is a drum core, wirewound inductor in the LQH43 series, offering 1.2 µH inductance with ±10% tolerance. Rated for 1.1 A continuous current and a maximum DC resistance of 51.6 mOhm, it is built for power filtering and DC-DC converter output stages where low loss and stable inductance matter.
What the key ratings mean for your BOM
The 1.1 A current rating is the saturation-limited DC current at which inductance typically drops 10% — for a 12 V to 3.3 V buck converter delivering 0.8 A, this inductor stays well within its linear region, but a 1.2 A load would push it into saturation and raise ripple current. 51.6 mOhm max DCR at 25°C translates to about 62 mW of I²R loss at 1.1 A — negligible for most boards, but if the inductor sits in a high-ambient engine bay (105°C), the copper resistance rises roughly 40%, pushing losses to ~87 mW and raising the winding temperature above the 125°C limit. Self-resonant frequency of 100 MHz means the inductor behaves inductively up to about 10-20 MHz in a typical buck converter — above that, parasitic capacitance between windings turns it capacitive, so it should not be used as a filter choke above 20 MHz.
The ferrite core is unshielded, so magnetic coupling to adjacent traces or components is a real concern; keep sensitive analog or RF traces at least 5 mm away, or switch to a shielded variant in the same series.