39 µH wirewound inductor for DC-DC filtering and bias-T circuits
The Murata LQH43MN390J03L is a 39 µH drum-core wirewound inductor in the LQH43 series, packaged in an 1812 (4532 metric) surface-mount footprint. Rated for 240 mA continuous current with a maximum DC resistance of 1.4 Ohm, this part suits low-to-moderate current filtering in DC-DC converter output stages, bias-T networks, and signal-line noise suppression where the inductance value and tolerance (±5%) need to be held tight.
Unshielded construction and self-resonant frequency
The unshielded drum-core design means the magnetic field extends beyond the component body — adjacent traces and components should be kept at a distance to avoid coupling, especially in dense layouts. Self-resonant frequency is 11 MHz; above this the inductor behaves capacitively, limiting the useful band to roughly DC–10 MHz for impedance-based filtering. Quality factor is 35 at 1 MHz test frequency, indicating moderate AC loss at that point — adequate for general-purpose filtering but not optimized for high-Q resonant tank circuits.
Thermal and mechanical fit for 1812 pads
Operating temperature range is -40°C to +85°C, covering most commercial and industrial indoor environments but not extended automotive or high-temp applications.