2.7 µH drum core inductor for power and signal filtering
The Murata LQH43NN2R7M03L is a drum core, wirewound inductor in the LQH43 series, rated 2.7 µH at 1 MHz test frequency with ±20% tolerance. It carries a continuous current rating of 500 mA, which is the DC current at which the inductance drop and temperature rise remain within the datasheet limits. Maximum DC resistance of 320 mOhm defines the I²R conduction loss at full load — at 500 mA the self-heating is roughly 80 mW, which is manageable in a standard 1812 footprint but should be factored into the thermal budget for dense boards. The unshielded construction means magnetic flux radiates from the core — adjacent traces carrying sensitive analog signals or high-impedance nodes should be kept at least one body width away to avoid coupling.
Frequency response and Q factor
Self-resonant frequency of 53 MHz sets the upper bound for inductive behaviour — above this frequency the parasitic capacitance dominates and the component behaves as a capacitor. For power rail filtering, keep the ripple frequency below 10-15 MHz to stay well within the inductive region. Q factor of 20 at 1 MHz gives a measure of the inductor's AC loss in resonant or filter circuits — higher Q means narrower bandwidth and less energy dissipated per cycle. For a simple LC filter at 1 MHz, the -3 dB bandwidth is approximately f₀/Q, or about 50 kHz.
Active production and sourcing posture
For BOM placement, the part is sourced to order against the required quantity.