610 nH wirewound inductor for RF and bias-T applications
The Murata LQH31HNR61J03L is a drum core, wirewound inductor in the LQH31 series, offering 610 nH ±5% inductance in a standard 1206 (3216 Metric) surface-mount package. Rated for 250 mA continuous current with a maximum DC resistance of 624 mOhm, this part is sized for RF bias feeds, impedance matching networks, and low-current filtering where the DCR contributes a 156 mV drop at full rated current.
Self-resonant ceiling and Q factor
A self-resonant frequency of 240 MHz places the usable inductance band well below that ceiling — for RF designers, the inductor behaves inductively up to roughly 80% of SRF, so this part is a solid choice for VHF-band matching up to about 190 MHz. The Q factor of 60 at 100 MHz indicates moderate efficiency in resonant tank circuits; the loss tangent at that frequency is low enough for narrowband RF front-end filtering but not for high-Q oscillator tanks where Q > 100 is typically required.
Unshielded construction and layout implications
This is an unshielded inductor, meaning the magnetic field radiates from the drum core. In a dense RF layout, keep sensitive traces and ground pours at least one part width away to avoid parasitic coupling — the 3.20 × 1.60 mm footprint gives about 3 mm clearance for a 20 dB isolation rule of thumb. The ferrite core material provides stable inductance over temperature but saturates at a lower DC bias than an air-core; the 250 mA rating already accounts for the saturation knee at room temperature.
Last Buy lifecycle — sourcing reality
Murata has marked the LQH31HNR61J03L as Last Buy, meaning official production is ending and no further factory orders are being accepted. No official successor or pin-compatible alternative is recorded for this order code. For a BOM line requiring this exact inductance, tolerance, and package, the available surplus inventory is the primary supply path.