1 µH, 3.1 A, 70 mOhm — the saturation and loss trade-off
The DFE201610P-1R0M=P2 is a shielded wirewound power inductor from Murata's DFE201610P series, built on an iron powder drum core. Its 1 µH nominal inductance carries a ±20% tolerance, measured at 1 MHz — the actual value at the test frequency can range from 0.8 µH to 1.2 µH before DC bias is applied. The 3.1 A current rating is the saturation current — the DC current at which inductance typically drops by 30%. The iron powder core saturates more gradually than ferrite, so the inductance roll-off under bias is softer, which matters when the peak current exceeds the nominal load current during startup or transient events. The 70 mOhm maximum DCR sets the copper loss: at 3.1 A the I²R dissipation is 0.67 W.
Shielded construction and temperature range
The magnetic shield reduces radiated EMI, allowing placement near other inductors, switching nodes, or sensitive analog traces without cross-coupling. This is a practical advantage in dense power rails for POL converters or module inputs where board area is tight. The iron powder core's Curie temperature is well above this range, so inductance stability over temperature is dominated by the winding copper's temperature coefficient of resistance — DCR rises roughly 0.4% per °C, increasing the I²R loss at high ambient.