## Analysis of FP1109-R23-R (Power Inductor) The **FP1109-R23-R** is a high-current, shielded drum core power inductor manufactured by **Eaton (formerly Cooper Bussmann/Coiltronics)**. It is part of the FP1109 series, designed specifically for high-frequency voltage regulator modules (VRMs). ### 1. Key Specifications The technical parameters for this specific part number are detailed below: | Parameter | Value | | :--- | :--- | | **Inductance** | 230 nH (0.23 µH) | | **Tolerance** | ±10% | | **DC Resistance (DCR)** | 0.42 mΩ (Max) | | **Saturation Current ($I_{sat}$)** | 45 A | | **RMS Current ($I_{rms}$)** | 36 A | | **Operating Temperature** | -40°C to +125°C | | **Package / Case** | 11.0mm x 9.0mm x 9.0mm (SMD) | --- ### 2. Physical & Material Characteristics * **Core Material:** Ferrite core. Ferrite provides low core losses at high frequencies, which is essential for modern power conversion. * **Construction:** It features a "Flat-Pac" design. This utilizes a flat wire construction which significantly reduces the DC resistance (DCR) compared to round wire, allowing for higher current handling without overheating. * **Shielding:** The component is magnetically shielded to minimize Electromagnetic Interference (EMI) with surrounding components on the PCB. --- ### 3. Common Applications Due to its high saturation current and extremely low DCR, the FP1109-R23-R is typically used in: * **Multi-phase buck regulators:** Used in CPU/GPU power supplies. * **Voltage Regulator Modules (VRM):** For servers and workstations. * **Desktop and Notebook Regulators:** High-efficiency DC-DC converters. * **Point-of-Load (POL) Converters:** Providing stable power near the load. --- ### 4. Part Number Breakdown The naming convention follows the Eaton/Coiltronics standard: | Segment | Meaning | | :--- | :--- | | **FP** | Product Series (Flat-Pac Inductor) | | **1109** | Physical size (approx. 11mm x 9mm) | | **R23** | Inductance value (R23 = 0.23 µH) | | **-R** | RoHS compliant / Lead-free | ---