47 µH unshielded wirewound — DC bias and loss budget
The LQH43CN470K03L is a drum-core wirewound inductor in the LQH43 series, rated 47 µH ±10% at 1 MHz test frequency. The unshielded construction means the flux field extends beyond the component body — keep sensitive traces or adjacent magnetics at least one package width away to avoid coupling. DC current rating of 280 mA is the bias at which inductance typically drops by 10 %; above that the core begins saturating and the effective inductance falls off. The 1.1 Ω max DCR translates to roughly 86 mW self-heating at full rated current — negligible in free air but relevant in a dense 1812 array. Self-resonant frequency of 10 MHz sets the upper bound for filtering applications. Below SRF the component behaves as an inductor; near or above it the parasitic capacitance dominates and the impedance becomes capacitive. For a buck converter switching at 2 MHz, this part stays well within the inductive region with margin.
For applications requiring continuous ambient above 85 °C, a higher-temperature-grade inductor (e.g., Murata's LQH43C_ series with extended temp) would be needed.