330 µH wirewound for filtering and bias-T applications
The Murata LQH43NN331K03L is a drum-core wirewound inductor offering 330 µH ±10% in the standard 1812 (4532 Metric) surface-mount footprint. It is part of the LQH43 series, built on a ferrite core with an unshielded construction. Rated at 95 mA DC, the inductor's 8.2 Ohm maximum DCR sets the resistive loss at full load — a 95 mA current through 8.2 Ohm dissipates about 74 mW, which is manageable within the 1812 package's thermal budget at 105°C ambient.
Self-resonant frequency and frequency-domain fit
With a self-resonant frequency of 3.6 MHz, this inductor behaves inductively up to that point; above it the impedance turns capacitive. The Q factor of 40 at 796 kHz indicates moderate energy storage efficiency in the low-MHz range, typical for a wirewound part at this inductance. The inductance is tested at 1 MHz, confirming the part is characterized for switching frequencies and filter designs near that point. For a supply decoupling or bias-T application at 1–3 MHz, the 330 µH value provides a high impedance to AC ripple while passing the DC bias current.
Package, temperature range, and layout considerations
The unshielded design means the magnetic field radiates — adjacent traces carrying sensitive analog signals or high-impedance nodes should be kept at least one body width away to avoid coupling. The ferrite core material maintains stable inductance across this range, though DCR rises with temperature per the copper winding's positive temperature coefficient.
Sourcing and supply posture
It is available through independent distribution channels, quoted to order against BOM quantities. The base product number LQH43NN covers the full series; the suffix K03L denotes the 330 µH ±10% variant. Tape-and-reel packaging (Cut Tape also available) supports both prototype and production volumes.