68 µH shielded power inductor for DC-DC rail filtering
The Murata LQH3NPN680MMEL is a 68 µH shielded wirewound inductor in the LQH3 series, built for surface-mount power-supply filtering and DC-DC converter output stages. Rated for 470 mA continuous current with a saturation floor of 310 mA (Isat) — the usable current in a buck or boost rail is limited by the saturation point, not the thermal rating, because inductance collapses above Isat. The 1.15 Ohm DC resistance sets the I²R loss at full load to about 0.25 W — fine for a 3×3 mm footprint, but the temperature rise at 470 mA continuous should be checked against the 105 °C operating ceiling in a tight enclosure.
Self-resonant frequency and board-level fit
Self-resonant frequency is 5 MHz — above that the part behaves capacitively, so keep the switching frequency of the downstream converter below 2.5 MHz to stay in the inductive region with margin. The 1212 (3030 Metric) package with 3.00 mm × 3.00 mm footprint and 1.50 mm seated height fits standard pick-and-place; the ferrite core and full shielding reduce radiated EMI into adjacent traces on a mixed-signal board. Inductance is tested at 1 MHz — the 68 µH value is nominal at that frequency; actual inductance at the converter's switching frequency may differ slightly due to core permeability roll-off.