What the 4.7 µH rating means for your filter or DC-DC circuit
The LQH31MN4R7J03L is a Murata drum core wirewound inductor from the LQH31 series, offering 4.7 µH inductance with ±5% tolerance. The 120 mA current rating and 2.21 Ω max DCR define the practical load: at 120 mA the copper loss is about 32 mW, acceptable for low-power signal filtering or DC-DC output smoothing in a 1206 footprint. The self-resonant frequency of 31 MHz and Q factor of 35 at 8 MHz indicate useful performance well into the HF band — suitable for RF bias-T or impedance matching up to tens of MHz, though the unshielded construction means magnetic coupling to nearby traces must be considered in layout.
Last-buy lifecycle — plan your procurement now
Murata has placed the LQH31MN4R7J03L on last-buy status. This means the manufacturer will accept final orders within a defined window; after that, supply shifts to independent surplus channels. If this inductor is on your BOM, secure your lifetime buy or a multi-year buffer before the order cutoff closes. The LQH31 series itself may have active variants with similar inductance and current ratings, but pin-compatibility and footprint must be verified against your specific layout — the 1206 case size is standard, but a drop-in replacement is not guaranteed.
The ferrite core and wirewound construction are surface-mount compatible with standard reflow profiles. Operating temperature range is -40°C to +85°C, covering industrial and most commercial environments. The unshielded design means the inductor radiates magnetic flux — keep sensitive traces or low-impedance loops at least a few millimeters away in layout.