18 µH filter choke for DC-DC input/output rails
The Murata LQH2MCN180M52L is a drum-core wirewound inductor in the LQH2 series, rated 18 µH ±20% with a 140 mA current rating. An 18 µH value at 140 mA suits low-current DC-DC converter input/output filtering — think sensor rail smoothing or MCU local supply decoupling where the load stays under 100 mA continuous. The 5.2 Ohm max DCR means conduction loss at full rated current is about 102 mW — the inductor self-heats inside the 0806 footprint, so keep the trace copper pour under the part to help sink that heat.
0806 footprint and board-fit check
Unshielded construction — magnetic flux couples into adjacent traces and components. In a mixed-signal layout, place the inductor at least 3–5 mm from sensitive analog or RF signal paths to avoid noise injection. Self-resonant frequency at 30 MHz — the inductor behaves as an inductor up to about 10–15 MHz; above that the parasitic capacitance dominates. For a 1–2 MHz switching converter the SRF is cleanly above the switching harmonics.
Temp range and sourcing posture
Operating temperature -40 °C to +85 °C covers industrial and commercial environments — outdoor telecom cabinets, factory-floor sensor nodes, and office power supplies all fall inside this band.