1.5 µH drum core for power and signal filtering
The Murata LQH43MN1R5M03L is a 1.5 µH drum-core wirewound inductor in the LQH43 series, rated for 500 mA continuous current with a maximum DC resistance of 300 mOhm. The unshielded ferrite core and 85 MHz self-resonant frequency suit it for DC-DC converter output filtering and low-frequency signal decoupling where the 500 mA current ceiling and 300 mOhm DCR are within the rail budget.
What the ratings mean for your BOM
The 500 mA current rating is the maximum DC current before inductance drops 10% typically — staying below this keeps the 1.5 µH value stable. The 300 mOhm DCR at 500 mA produces a 75 mW I²R loss, which is manageable in the 1812 body but contributes to self-heating in a confined layout. A Q factor of 20 at 1 MHz indicates moderate efficiency at that frequency — the inductor is not optimised for high-Q resonant tanks but works well for bulk power filtering where the 85 MHz SRF gives adequate margin above the switching frequency of a typical buck converter. The unshielded construction means magnetic flux radiates — keep sensitive traces or other magnetics at least a few mm away in the layout.