The **FP0708R1-R09-R** is a high-current, shielded drum core power inductor manufactured by **Eaton (formerly Cooper Bussmann)**. It belongs to the **FP0708 series**, which is designed specifically for high-frequency voltage regulator modules (VRMs). ### 1. Technical Specifications The part number encodes the specific performance characteristics of the component: | Characteristic | Specification | | :--- | :--- | | **Inductance (L)** | 90 nH (0.09 µH) | | **Tolerance** | ±10% | | **Full Load Current ($I_{sat}$)** | ~82 Amps (at 25°C) | | **DC Resistance (DCR)** | 0.42 mΩ (Max) | | **Operating Temperature** | -40°C to +125°C | | **Package Size** | 7.0 x 8.0 x 7.5 mm | --- ### 2. Physical Construction The inductor is built using a **ferrite core** with a "drum" design. Its construction features include: * **Vertical Orientation:** Designed for a small PCB footprint while maintaining high inductance density. * **Shielded Design:** Uses a magnetic shield to minimize Electromagnetic Interference (EMI) with neighboring components. * **Surface Mount (SMT):** Lead-free and RoHS compliant for standard reflow soldering processes. --- ### 3. Key Performance Features The FP0708R1-R09-R is optimized for power density and efficiency: * **High Saturation Current:** It can handle high peak currents without the inductance dropping significantly, which is critical for preventing circuit failure during heavy loads. * **Ultra-Low DCR:** The 0.42 mΩ resistance ensures minimal power loss through heat (Joule heating), maximizing the efficiency of the power supply. * **Controlled Roll-off:** The inductance stays relatively flat over a wide range of current levels. --- ### 4. Typical Applications This specific inductor is found in high-performance computing environments: 1. **Multi-phase Buck Converters:** Used in power stages for CPUs and GPUs. 2. **Voltage Regulator Modules (VRM):** Specifically for servers and workstations. 3. **Data Center Infrastructure:** Switched-mode power supplies (SMPS) for high-speed networking equipment. --- ### Part Number Breakdown The nomenclature can be interpreted as follows: * **FP**: Ferrite Patch / Flat-Pac series. * **0708**: Physical dimensions (approx. 7mm x 8mm). * **R1**: Revision or variation code. * **R09**: Inductance value (R09 = 0.09 µH or 90 nH). * **-R**: RoHS compliant.