560 µH wirewound inductor for low-current filtering
The Murata LQH32MN561K23L is a drum core wirewound inductor in the LQH32 series, offering 560 µH inductance with ±10% tolerance. It is rated for 40 mA continuous current, making it suitable for filtering and energy storage in low-power DC-DC converters and signal conditioning circuits. The unshielded construction keeps the part cost low, but the open magnetic field means it should be placed away from sensitive traces or other inductors to avoid coupling.
What the key ratings mean for your BOM
The 560 µH inductance at 1 MHz test frequency is the nominal value; the self-resonant frequency of 5 MHz sets the upper bound for effective filtering — above that the inductor behaves capacitively. For a buck converter switching at 500 kHz, this part provides good ripple attenuation, but at 2 MHz the margin shrinks. The 40 mA current rating is the DC current at which the inductance typically drops by 10% due to saturation. The 28 Ohm maximum DCR means a 40 mA load produces a 1.12 V drop across the inductor — significant in a 3.3 V rail, so the voltage budget must account for this loss. A Q factor of 50 at 796 kHz indicates moderate efficiency at that frequency; the Q peaks near the self-resonant frequency, so the part is most efficient for filtering in the 1-3 MHz range.
The nonstandard case designation means the pad layout should follow the manufacturer's recommended land pattern, not a generic 1210 footprint. It is supplied on tape and reel (cut tape available), compatible with standard pick-and-place assembly. The unshielded construction means no magnetic shielding layer, so the part is lighter but more prone to radiated noise.