6.8 µH Shielded Wirewound — DC-DC Output Filter Fit
The Murata LQH3NPN6R8MGRL is a 6.8 µH, ±20% tolerance, shielded drum-core wirewound inductor in the LQH3 series, housed in a 1212 (3030 Metric) surface-mount package. Its 680 mA continuous current rating and 276 mOhm max DCR define the I²R loss budget — at full rated current the copper loss is 128 mW, which must be factored into the local temperature rise against the 105°C ambient ceiling. The 720 mA saturation current (Isat) sits 5.9% above the rated current — a tight margin typical of small-footprint shielded inductors. In a buck converter output filter, the peak-to-peak ripple current plus DC bias must stay below Isat or the inductance collapses, increasing ripple and stressing the output capacitor.
25 MHz Self-Resonant Frequency — Usable Band Limit
The self-resonant frequency (SRF) of 25 MHz marks the upper bound where the inductor's parasitic capacitance cancels the inductive reactance. Above SRF the component behaves capacitively — for a 2.2 MHz switching regulator, the inductor operates well below SRF with margin; for a 10 MHz converter the margin is narrow and the effective inductance near SRF will deviate from the 1 MHz test value. The ferrite core material and shielded construction suppress radiated EMI — relevant when the inductor sits adjacent to sensitive analog or RF circuitry on the same board. The 3.00 mm × 3.00 mm footprint with a 1.00 mm seated height fits standard pick-and-place and low-profile power rail layouts.