56 µH wirewound inductor for DC-DC input/output filtering
The Murata LQH43MN560K03L is a drum-core wirewound inductor rated 56 µH ±10% with a 200 mA current rating and a 1.7 Ohm max DCR. The unshielded ferrite-core construction is common in power-supply input/output filter stages and low-current DC-DC converter output chokes where the board layout keeps the magnetic field away from sensitive traces.
What the Q factor and self-resonant frequency mean for the filter
The Q factor is 35 at 1 MHz and the self-resonant frequency is 9.3 MHz. The SRF sets the upper bound for useful inductance — above SRF the inductor behaves capacitively. For a buck-converter switching at 500 kHz, the 56 µH value holds its impedance into the low MHz range before the parasitic capacitance takes over. The 1.7 Ohm max DCR at 200 mA means roughly 68 mW of I²R loss at full rated current — negligible for most low-power rails, but the unshielded construction means the external field couples into adjacent PCB traces, so the inductor should sit away from feedback dividers or analog signal paths.