1.5 mH at 40 mA — the limiting axis for this LQH43 inductor
The Murata LQH43NN152K03L is a drum-core wirewound inductor from the LQH43 series, rated 1.5 mH ±10% with a continuous current ceiling of 40 mA. The 37 Ohm max DC resistance means the IR drop at full rated current is about 1.48 V — that is the self-heating floor before ambient temperature is factored in, and it sets the voltage budget for the series resistor in an LC filter or the DC bias loss in a choke application.
Unshielded ferrite core — magnetic coupling is a layout variable
The ferrite core is unshielded, so the magnetic field extends beyond the component body. In a dense 1812 SMD layout, adjacent traces carrying high-frequency signals may pick up coupled noise — keep a keep-out zone around the inductor or orient it orthogonal to sensitive traces. The self-resonant frequency is 1.6 MHz; above that the inductive reactance rolls off and the part behaves capacitively, so the usable filtering band stops well below that point. Q factor is specified at 40 at 252 kHz — that is the efficiency sweet spot for this winding. Below 100 kHz the Q drops as core losses dominate; above 1 MHz the winding AC resistance rises and the Q falls again. For a resonant tank or a tuned filter, the operating frequency should sit near the Q peak.
The 1812 footprint is a standard size shared across the LQH43 family, so a different inductance value in the same series can be swapped in without a board spin if the design requirements shift.