27 µH wirewound for DC-DC filtering and bias-T networks
The Murata LQH31MN270J03L is a drum-core wirewound inductor in the LQH31 series, wound on a ferrite core and terminated in a 1206 (3216 metric) SMD package. Its 27 µH inductance at 1 MHz test frequency, ±5% tolerance, suits it for DC-DC converter output filtering, bias-T decoupling, and low-current signal conditioning where a predictable inductance value matters more than the highest saturation current.
Rated current and DCR — the real limits on the BOM line
Rated at 85 mA continuous, this is the current at which the inductance typically drops by 10% from the nominal value due to core saturation — stay below this figure in the steady-state load to keep the filter corner frequency where the simulation expects it. DC resistance is 3.4 Ohm, which at 85 mA drops 289 mV across the part and dissipates 24.6 mW — negligible for the board thermal budget, but the voltage drop matters if the inductor sits in a low-voltage rail where every millivolt counts. Self-resonant frequency is 13 MHz; above that the impedance becomes capacitive, so this part is best kept below 10 MHz in a switching regulator or filter application. The Q factor is 40 at 2.5 MHz, indicating moderate AC loss in that band.
Active production and sourcing posture
Operating temperature range is -40°C to +85°C, which covers most indoor and outdoor telecom, industrial control, and consumer equipment but does not reach the +105°C or +125°C grades needed for under-hood automotive or high-ambient power supplies.