4.7 µH, 8.8 A Shielded Power Inductor — AEC-Q200
The Murata DFEH10040D-4R7M=P3 is a 4.7 µH shielded power inductor from the DFEH10040D series, rated for 8.8 A continuous current with a saturation current of 9.3 A. The narrow 0.5 A headroom between rated and saturation current means the inductor saturates quickly once the DC bias exceeds the rated current — the designer must size the ripple current margin accordingly in a buck converter's inductor selection. Qualified to AEC-Q200, the part operates from -40°C to 155°C, covering under-hood and powertrain temperature profiles in automotive ECUs. The iron powder core and shielded construction keep the magnetic field contained, reducing EMI coupling to adjacent power traces in a dense PCB layout.
Parametric Fit for DC-DC Converter Design
With a maximum DC resistance of 16 mOhm, the I²R conduction loss at 8.8 A is about 1.24 W — a thermal consideration for the 4.00 mm seated height in a forced-air or natural-convection environment. The 100 MHz test frequency for inductance is typical for power inductors; the actual inductance at the converter's switching frequency (typically 200 kHz to 2 MHz) will be slightly higher than the 4.7 µH value due to the core's frequency-dependent permeability. Tolerance is ±20%, which is typical for power inductors and must be accounted for in the output ripple voltage calculation.
Obsolete — Sourcing Through Independent Channels
Murata has marked the DFEH10040D-4R7M=P3 as obsolete. For a BOM line that requires this exact inductance, current rating, and footprint, the supply posture is last-time-buy inventory — no guarantee of replenishment once existing stock is exhausted. The AEC-Q200 qualification and 155°C rating make this a candidate for automotive or high-temp industrial designs that are already in production and cannot easily respin the PCB. A design-in for a new project should consider a current-production alternative from the same series or a competitor's shielded power inductor family.