The **FP1105R1-R22-R** is a high-performance, high-current power inductor typically used in DC-DC converter applications, specifically in Voltage Regulator Modules (VRMs). It is part of the FP1105 series manufactured by Eaton (formerly Cooper Bussmann/Coiltronics). --- ### 1. Key Technical Specifications | Parameter | Value | | :--- | :--- | | **Inductance** | 0.22 µH (220 nH) | | **Tolerance** | ±10% | | **Saturation Current ($I_{sat}$)** | 61 Amperes | | **RMS Current ($I_{rms}$)** | 43 Amperes | | **DC Resistance ($DCR$)** | 0.42 mΩ (Max) | | **Operating Temperature** | -40°C to +125°C | | **Package Type** | Surface Mount (SMD) | | **Dimensions** | 11.0mm x 8.0mm x 4.9mm | --- ### 2. Physical Construction The "FP" in the part number stands for **Flat-Pac**. This series uses a unique construction style: * **Core Material:** Ferrite core, which offers low core losses at high frequencies. * **Winding:** Utilizes a flat wire (foil) winding. This increases the surface area, reducing the **Skin Effect** and significantly lowering the DC Resistance (DCR). * **Shielding:** It is a magnetically shielded design, which minimizes Electromagnetic Interference (EMI) with surrounding components on a dense PCB. --- ### 3. Part Number Breakdown The nomenclature provides specific details about the component: | Code Segment | Meaning | | :--- | :--- | | **FP1105** | Series name and physical size (11mm x 8mm x 5mm approx) | | **R1** | Version/Revision code (specific to mechanical or material internal specs) | | **R22** | Inductance value: "R" acts as a decimal point. $0.22 \mu H$ | | **-R** | RoHS compliant (Lead-free) | --- ### 4. Typical Applications This specific inductor is designed for "Point of Load" (POL) power supplies where high current and high efficiency are required in a small footprint: * **Servers and Workstations:** Multi-phase buck converters for CPU/GPU power. * **Networking Equipment:** High-speed routers and switches. * **Voltage Regulator Modules (VRM):** Converting 12V down to sub-1V levels for microprocessors. * **Graphics Cards:** High-power power stages. --- ### 5. Benefits 1. **High Efficiency:** The extremely low DCR (0.42 mΩ) minimizes power loss due to heat ($P = I^2R$). 2. **Stable Saturation:** The ferrite material provides a "sharp" saturation curve, but it is rated to handle very high peak currents (up to 61A) before the inductance drops significantly. 3. **Space Saving:** The vertical/compact integration allows for high power density on crowded circuit boards.