3.3 µH drum core for power and signal filtering
The LQH43NN3R3M03L is a drum core, wirewound inductor from Murata's LQH43 series, offering 3.3 µH inductance with ±20% tolerance in an unshielded 1812 (4532 Metric) SMD package. Rated for 500 mA DC current with a maximum DCR of 350 mOhm, the part suits low-to-moderate current paths where conduction loss and self-heating must be budgeted — at full rated current, I²R loss is about 87.5 mW, which is manageable in free-air on a standard PCB. The self-resonant frequency of 47 MHz defines the upper bound for inductive behavior; above this frequency the component becomes capacitive, so it is best applied in DC-DC converter output filters or signal-line chokes operating well below 47 MHz.
Operating range and board integration
The 1812 footprint (4.50 mm x 3.20 mm, seated height 2.80 mm) is a common size for power inductors, allowing straightforward board layout reuse with other 1812 SMD inductors from the same or competing families. The unshielded construction means magnetic flux radiates from the component — keep sensitive analog or RF traces at least one package width away to avoid coupling.