820 µH ferrite-core wirewound for signal filtering
The Murata LQH43NN821J03L is a drum-core wirewound inductor in the LQH43 series, delivering 820 µH ±5% in an unshielded 1812 (4532 Metric) SMD package. Rated for 60 mA continuous current with a maximum DC resistance of 20.5 Ohm, it is sized for low-current filtering and decoupling applications where the inductance value matters more than the current handling.
Q factor and self-resonant frequency
The Q factor is 40 at 796 kHz, giving a measure of the inductor's efficiency at that test frequency — higher Q means lower energy loss per cycle in tuned circuits. Self-resonant frequency is 2.2 MHz; above this point the inductor behaves capacitively, so the useful filtering range stops well below that ceiling. Inductance is tested at 1 kHz, confirming the value holds in the low-frequency audio and power-supply ripple band.