The **47DR-1018-R** is a specific surface-mount device (SMD) power inductor, commonly used in high-density electronic circuits. Below is a detailed breakdown of its specifications and characteristics. ### 1. General Specifications The part number follows a standard convention used by manufacturers like **Coiltronics (Eaton)**. | Parameter | Specification | | :--- | :--- | | **Component Type** | Shielded Power Inductor | | **Inductance** | 18 µH (Microhenries) | | **Inductance Code** | 1018 (where '18' denotes the value) | | **Mounting Type** | Surface Mount (SMD/SMT) | | **RoHS Compliant** | Yes (indicated by the "-R" suffix) | --- ### 2. Physical and Electrical Properties * **Shielding:** This is a **shielded** inductor. It is encased in a magnetic material (usually ferrite) to contain the magnetic field. This minimizes Electromagnetic Interference (EMI) with neighboring components on the PCB. * **Core Material:** Typically uses a ferrite core, which provides high efficiency and low core losses at switching frequencies. * **Dimensions:** The "47" in the prefix usually refers to the physical size series (e.g., approximately 4.0mm x 4.0mm or similar footprint depending on the specific manufacturer's catalog). --- ### 3. Key Performance Metrics | Feature | Description | | :--- | :--- | | **DCR (DC Resistance)** | Designed to be low to minimize power dissipation (heat) and improve efficiency. | | **Saturation Current ($I_{sat}$)** | The current level at which the inductance drops by a specified percentage (usually 30%). | | **RMS Current ($I_{rms}$)** | The continuous current the inductor can handle without exceeding a specific temperature rise (usually 40°C). | --- ### 4. Common Applications The 47DR-1018-R is versatile but primarily found in power management stages: 1. **DC-DC Converters:** Used in "Buck" (Step-down) or "Boost" (Step-up) regulators. 2. **Point of Load (POL) Converters:** Providing stable voltage to CPUs or FPGAs. 3. **Battery Powered Devices:** Due to its small footprint and high efficiency. 4. **Filtering:** Used in LC filters to smooth out voltage ripples in power supplies. --- ### 5. Identification Example If you are looking at the marking on the physical part: * **180**: Often represents 18 µH (18 + zero additional zeros). * **R**: Indicates the part is lead-free and meets environmental standards.