The **FP1005R4-R12-R** is a high-performance, high-current power inductor typically used in multi-phase voltage regulator modules (VRMs). It belongs to the Eaton (formerly Cooper Bussmann/Coiltronics) **FP1005** series. --- ### 1. Technical Specifications The part number reveals the specific electrical characteristics of the component: | Parameter | Specification | | :--- | :--- | | **Inductance (L)** | 120 nH (0.12 µH) | | **Tolerance** | ±10% | | **Full Load Current ($I_{sat}$)** | ~53 Amps (at 25°C) | | **DCR (Direct Current Resistance)** | 0.29 mΩ (Typical) | | **Frequency Range** | Up to 2 MHz | | **Dimensions** | 10.2 x 7.0 x 4.95 mm | --- ### 2. Breakdown of the Part Number The nomenclature follows a specific logic used by the manufacturer: * **FP1005:** Series name (Flat-Pac), where numbers represent the physical size (approx. 10mm x 5mm footprint). * **R4:** Indicates the version or revision (Version 4). * **R12:** Represents the inductance value. `R` denotes the decimal point (0.12 µH). * **-R:** Indicates RoHS compliance. --- ### 3. Key Design Features * **Ferrite Core Material:** Provides low core losses at high switching frequencies, making it ideal for high-efficiency DC-DC converters. * **Vertical Mounting:** The design uses a "Flat-Pac" structure with a small footprint to save PCB real estate. * **High Saturation Current:** It is designed to handle very high current spikes without the inductance dropping significantly (magnetic saturation). * **Low DCR:** The use of flat wire or specialized winding ensures extremely low resistance, reducing heat generation and power waste. --- ### 4. Common Applications This inductor is specifically engineered for high-density power environments: 1. **Server & Networking:** Voltage regulators for CPUs, GPUs, and ASICs. 2. **Graphics Cards:** High-end GPU power delivery stages. 3. **Data Centers:** Distributed power systems and point-of-load (POL) converters. 4. **Desktop Computing:** Vcore power modules for high-performance motherboards. --- ### 5. Footprint/Layout Example When designing a PCB for this part, the landing patterns usually look like this: ```markdown [PAD 1] --- 2.54mm --- [PAD 2] | | |--- Body: 10.2mm L -----| ```