100 µH at 160 mA — what the ratings mean for your DC-DC rail
The LQH43NN101K03L is a 100 µH drum core wirewound inductor from Murata's LQH43 series, unshielded, in a standard 1812 (4532 Metric) SMD package. Rated at 160 mA continuous, the inductor's current ceiling is set by the 2.5 Ohm max DCR — at full load the copper loss is I²R = 64 mW, which raises the internal temperature roughly 15-20°C above ambient in free air, so derate the current by 10-15% if the board sees 85°C or higher. The self-resonant frequency of 6.8 MHz means the inductor behaves inductively up to that point; above 6.8 MHz the parasitic capacitance dominates and the impedance drops — keep the switching frequency of your buck or boost converter below 2-3 MHz to stay well clear of SRF.
Unshielded construction — where to place it and where not to
Because the part is unshielded, the magnetic field radiates from the drum core — keep a keep-out zone of at least 3-5 mm from sensitive analog traces, other inductors, and low-level signal paths to avoid crosstalk. The Q factor of 40 at 796 kHz is moderate — adequate for general-purpose filtering and energy storage in power supplies, but not for narrowband resonant circuits where a higher-Q (60+) part would reduce insertion loss.
The 1812 footprint is widely used across Murata's own LQH43 family and other manufacturers — if a second-source or alternate becomes necessary, the package and 100 µH / 160 mA rating are common enough to cross-reference without a board spin.