Inductance, current rating, and DC resistance
The LQH43NN222J03L is a 2.2 mH unshielded wirewound inductor from Murata's LQH43 series, rated for 30 mA continuous current with a maximum DC resistance of 50 Ohm. The 2.2 mH value and the 30 mA current rating define its role in filtering or energy-storage circuits where the load current stays below the DC bias saturation point.
1812 footprint and board-fit details
The ferrite core and unshielded construction mean the magnetic field extends beyond the package — keep adjacent traces and components clear of the inductor's stray field, especially in tightly packed RF or power supply layouts.
Frequency response and Q factor
A minimum Q of 40 at 252 kHz and a self-resonant frequency of 1.3 MHz set the usable band. Below 1.3 MHz the component behaves as an inductor; above that frequency parasitic capacitance dominates and the impedance turns capacitive. The Q at 252 kHz is high enough for tuned LC filter applications in that range, but the 50 Ohm DCR means the inductor is not a low-loss choice for high-current switching regulators.