470 µH filter choke for DC-DC and signal conditioning
The Murata LQH43NN471J03L is a 470 µH drum-core wirewound inductor in the LQH43 series, built for surface-mount filtering in power and signal paths where the DC current stays under 80 mA. Its 11.8 Ω max DC resistance means the I²R loss at full rated current is about 75 mW — acceptable for most low-power rails, but the voltage drop across the DCR matters if the inductor sits in a high-side supply line. The 3 MHz self-resonant frequency sets the upper bound for useful filtering; above that the component behaves capacitively, so it suits switching converters switching below 1 MHz and EMI line filters in the 100 kHz to 2 MHz band.
1812 footprint and rework considerations
Unshielded construction means the stray field couples into adjacent traces or components — keep a clearance of at least one part width from sensitive analog loops or RF paths.
Q factor and test conditions
Minimum Q of 40 at 796 kHz indicates the inductor's AC losses are moderate — adequate for resonant tank circuits or bandpass filters at that frequency, but a higher-Q part would be preferred for narrowband RF front-ends. Inductance is tested at 1 kHz, not at the self-resonant frequency; the 470 µH value holds within ±5 % tolerance at low frequency, but effective inductance drops as frequency approaches SRF.