270 µH, 65 mA — what the ratings mean for the BOM line
The Murata LQH32MN271J23L is a drum-core wirewound inductor in the LQH32 series, rated 270 µH at 1 MHz test frequency with ±5% tolerance. The 65 mA current rating is the DC bias current at which inductance typically drops 10% — stay below this to keep the filter corner where the schematic expects it. DC resistance is 12.5 Ohm max — at 65 mA the I²R loss is about 53 mW, negligible for most signal-filtering roles but a factor if this sits in a bias supply where every milliwatt counts. Self-resonant frequency is 5 MHz; above that the impedance rolls off as the parasitic capacitance dominates. Use this inductor below 2-3 MHz for a clean inductive response.
Unshielded construction — layout clearance matters
This is an unshielded drum-core inductor — the magnetic field extends beyond the body. Keep adjacent traces or copper pours at least 2-3 mm away to avoid coupling noise into nearby signal paths. In a dense 1210 layout, that clearance often means the inductor gets its own exclusion zone on the ground plane. The ferrite core material gives a Q factor of 40 at 796 kHz — moderate selectivity for tank circuits or bandpass filters at that frequency. Below 100 kHz the Q drops; above 1 MHz it rises until the core losses catch up.
Active lifecycle — no rush, but store the reels dry
Status is Active per Murata's product lifecycle — no last-time-buy notice, no successor announced. The LQH32 series is a long-running standard footprint, so second-sourcing from other 1210 ferrite-core wirewound inductors is straightforward if the BOM ever needs it. The reel is Tape & Reel (TR) with Cut Tape (CT) option; store below 30°C and 60% RH to keep the carrier tape from curling.