150 µH in a 1812 footprint — what the ratings mean for your BOM
The LQH43NN151K03L is a 150 µH unshielded wirewound inductor from Murata's LQH43 series, built on a ferrite drum core. The 130 mA current rating is the continuous DC limit at which the self-heating from the 3.7 Ohm DCR stays within the part's thermal budget — exceeding it risks saturating the core or cooking the winding insulation. At 130 mA and 3.7 Ohm, the I²R loss is about 62 mW — modest for a 1812 part, but in a dense board with limited airflow, that heat adds up. The unshielded construction means the magnetic field radiates; keep sensitive traces or other inductors a few body widths away to avoid coupling.
Board-fit: footprint, temperature, and frequency
Standard 1812 (4532 metric) land pattern — 4.50 mm × 3.20 mm body, 2.80 mm seated height. Self-resonant frequency is 5.5 MHz; the inductance is tested at 1 MHz. Below resonance the part behaves as an inductor; above it the impedance turns capacitive. For a 150 µH part, this SRF is typical and means it suits low-frequency filtering and DC-DC input/output ripple up to a few MHz. Q factor is 40 at 796 kHz — a moderate Q that gives reasonable selectivity for tuned circuits but not the sharp notch you would get from a high-Q air-core coil. The ±10% tolerance is standard for power-grade inductors; if your circuit needs tighter inductance matching, this is not the part.
Sourcing and lifecycle posture
This is a standard catalog inductor, not a custom or long-lead item. The base product number LQH43NN covers a family of values in the same 1812 footprint — if 150 µH is not the exact value your BOM calls for, a sibling in the same series shares the same land pattern and current rating envelope.