Inductance, current rating and the 1210 footprint
The LQH32MN391K23L is a drum-core wirewound inductor from Murata's LQH32 series, delivering 390 µH ±10% in the standard 1210 (3225 metric) SMD footprint. With a rated current of 50 mA and a maximum DC resistance of 22 Ω, the dc power loss at full current is I²R = 55 mW — a figure that sets the self-heating and derating margin in the application. The unshielded ferrite core means the magnetic field extends beyond the component body. In a dense layout, adjacent traces carrying high-frequency signals will couple into this inductor, and the inductor itself radiates a stray field that can inject noise into nearby loops — the PCB layout must keep a clearance zone around the part, especially under the 1210 land pattern.
Frequency band: where the Q factor and SRF matter
The Q factor is specified at 50 (minimum) measured at 796 kHz, and the self-resonant frequency (SRF) is 5 MHz. Below the SRF, the inductor behaves as a near-ideal inductance; above it, the parasitic capacitance between windings dominates and the component transitions to a capacitive impedance. For filtering roles, the usable band ends at roughly one-third the SRF, so this part is effective up to about 1.5–2 MHz. The inductance is tested at 1 MHz, confirming that the value holds within tolerance at that frequency — a useful reference for designers who need to know the inductance remains stable in the lower MHz range.
Operating temperature and production status
The temperature envelope does not extend into the +105°C or +125°C bands required for under-hood automotive or sealed outdoor enclosures with high self-heating. Lifecycle status is active per Murata's current product record — no end-of-life or last-time-buy notice is in effect for the LQH32MN391K23L. The base product number LQH32MN identifies the series; the suffix K23L encodes the inductance value, tolerance, and packaging variant.
Sourcing posture for volume and qualification
Sourced through authorized and independent distribution channels. No minimum order quantity is stated in the standard listing — volume requirements are handled per quote.