33 µH drum-core wirewound for DC-DC filtering
The Murata LQH43NN330J03L is a 33 µH drum-core wirewound inductor in the LQH43 series, built on a ferrite core with an unshielded construction.
Self-resonant frequency and Q factor
The self-resonant frequency is 12 MHz, and the Q factor measures 35 at 1 MHz test frequency. The Q value tells you the ratio of stored energy to dissipated energy at that frequency — a Q of 35 means the inductor behaves efficiently as a reactive element near 1 MHz, but above 12 MHz the parasitic capacitance dominates and the component becomes capacitive.
1812 SMD footprint and rework
The unshielded drum-core construction means the magnetic field radiates from the body — keep sensitive traces or other magnetics at least a body-width away to avoid coupling. The 1812 footprint is large enough for hand rework with tweezers and a soldering iron; the ferrite core is not thermally fragile, so it survives hot-air removal without cracking.
It is a standard-series part in the LQH43 family, widely used in power-supply filtering and signal conditioning circuits.