100 µH drum core wirewound — the loss and bandwidth trade-off
The LQH32DN101K23L is a 100 µH unshielded wirewound inductor from Murata's LQH32 series, built on a ferrite drum core. Rated current is 100 mA continuous, with saturation current matching the rated current at 100 mA — meaning the inductance holds until the current approaches the rated limit, then drops off sharply. DC resistance is 4.55 Ohm max, which at 100 mA produces a 45.5 mW I²R loss — negligible in a power rail filter but worth budgeting in a low-impedance supply path where every millivolt of drop counts. The self-resonant frequency is 10 MHz, so the inductive impedance dominates up to that point; above 10 MHz the part behaves capacitively and stops filtering.
No magnetic shield means the flux field extends beyond the component body. In a dense layout, adjacent traces or other inductors within a few millimetres can couple energy — keep a clearance of at least one part width (3.2 mm) to neighbouring magnetics or sensitive analog traces. The ferrite core material gives good temperature stability up to 105 °C, so the inductance shift across the -40 to +105 °C operating range stays within the ±10% tolerance band.
1210 footprint and tape-and-reel supply
The base product number LQH32DN covers the family; the full suffix 101K23L encodes the 100 µH value, ±10% tolerance, and packaging variant.