560 µH at 40 mA — the DC bias limit on this ferrite-core wirewound
The LQH32MN561J23L is a Murata Electronics drum-core, wirewound inductor in the LQH32 series, rated for 560 µH at 1 kHz test frequency with ±5% tolerance. The 40 mA current rating is the DC bias limit before inductance starts rolling off — push past it and the ferrite core saturates, dropping the effective inductance and turning the filter corner into a guess. For a low-power RF bias-T or a supply-line choke drawing 30 mA continuous, it holds the value; for a 50 mA load, the margin is gone. Unshielded construction means the magnetic field extends beyond the part body — adjacent traces or another inductor within a few millimeters pick up coupling. In a tight layout with a sensitive analog front-end or a radio VCO, the stray field can inject noise. The 5 MHz self-resonant frequency sets the upper bound: above that, the parasitic capacitance dominates and the part behaves more like a capacitor than an inductor, so keep the operating frequency well below 5 MHz. The Q factor of 50 at 796 kHz tells you the ratio of stored energy to loss per cycle at that frequency; useful if this inductor sits in a resonant tank or a tuned filter where the Q sets the bandwidth.
1210 footprint, 3.2 × 2.5 mm — board-fit checklist
The LQH32MN561J23L uses the standard 1210 (3225 metric) chip footprint — 3.20 mm long, 2.50 mm wide, 2.20 mm seated height. The nonstandard package designation means it does not follow the exact JEDEC 1210 body dimensions; check the Murata drawing for the land pattern. Reflow soldering with a typical lead-free profile works; the ferrite core handles the thermal shock without cracking if the ramp rate stays under 3°C/s. Surface-mount on standard FR-4 with 1 oz copper — the trace width to the pads should match the 40 mA rating comfortably at 0.3 mm or wider. No thermal pad or via array needed; the part dissipates through the solder joints and the body. Tape-and-reel packaging (cut tape or full reel) feeds into pick-and-place at standard 8 mm tape pitch.