The **FP1505R1-R40-R** is a high-current, flat-pac power inductor manufactured by Eaton (formerly Cooper Bussmann). It is primarily designed for high-frequency voltage regulator modules (VRMs) and DC-DC converters. ### Technical Specifications | Parameter | Value | | :--- | :--- | | **Inductance** | 400 nH (0.40 µH) | | **Tolerance** | ±10% | | **Saturation Current ($I_{sat}$)** | ~64 Amperes | | **RMS Current ($I_{rms}$)** | ~55 Amperes | | **DC Resistance (DCR)** | ~0.26 mΩ (Max) | | **Operating Temperature** | -40°C to +125°C | | **Package / Case** | Surface Mount (SMD) - 1505 size | --- ### Key Features and Construction 1. **Core Material:** It utilizes a ferrite core material. Unlike powdered iron cores, ferrite offers very low core losses at high frequencies, which is essential for modern efficiency standards. 2. **Flat-Pac Design:** The "1505" designation refers to the physical dimensions (approximately 15mm x 5mm). The low-profile design allows for better airflow and integration into space-constrained server motherboards. 3. **High Current Handling:** With an $I_{sat}$ of over 60A, this inductor can handle massive power surges without the inductance "dropping off" (saturating), which protects the downstream ICs. 4. **Low DCR:** The extremely low Direct Current Resistance (0.26 mΩ) minimizes power dissipation as heat, leading to higher overall system efficiency. --- ### Typical Applications This specific component is commonly found in: * **Multi-phase VRMs:** Used to power CPUs and GPUs in servers and high-end workstations. * **Point-of-Load (POL) Converters:** Decentralized power management on complex PCBs. * **Data Centers:** High-density power modules where thermal management is critical. --- ### Part Number Breakdown: `FP1505R1-R40-R` * **FP1505:** Series name and physical size (Flat-Pac, 15mm width). * **R1:** Revision or internal designator for the winding style. * **R40:** Inductance value (R40 = 0.40 µH). * **-R:** RoHS compliant (Lead-free).