68 µH, 50 mA — what the ratings mean for the board
The LQH31MN680K03L is a 68 µH drum-core wirewound inductor in the LQH31 series, rated for 50 mA continuous current with a maximum DC resistance of 12.87 Ohm. That DCR tells you the self-heating at rated current: at 50 mA, the copper loss is about 32 mW — negligible in most circuits, but if you push 60 mA through it the temperature rise accelerates because the DCR is already high for a 1206 package. The unshielded construction means the magnetic field extends beyond the component body. Keep it at least one part-width away from other inductors or sensitive analog traces to avoid coupling. The ferrite core material gives a self-resonant frequency of 8.5 MHz, so this part works best below a few MHz — above that the inductance rolls off as the core losses climb.
This part is in Last Buy status. Murata has announced end-of-life; the last-time-buy window is open now. If this inductor is on your BOM, you need to secure lifetime-buy quantities or qualify a replacement before the window closes. No official successor is listed — the closest functional alternative is another 68 µH wirewound in the same 1206 footprint, but the DCR and current rating will differ. Operating temperature range is -40°C to +85°C, which covers most indoor and outdoor equipment but not under-hood automotive or high-temp industrial enclosures. If your board sees sustained ambient above 85°C, this inductor is not the right choice — look for a part rated to 125°C or higher.