The **L817PW-R47MF** is a high-performance **surface-mount (SMD) power inductor**, typically used in DC-DC converter circuits to manage power flow and filter noise. It belongs to a class of metal-alloy molded inductors known for their high current density and low profile. --- ## Technical Specifications The part number follows a standard coding convention for power inductors. Below are the primary electronic characteristics: | Parameter | Value / Description | | :--- | :--- | | **Inductance** | 0.47 µH (indicated by "R47") | | **Tolerance** | ±20% (indicated by "M") | | **Material** | Metal Alloy / Carbonyl Powder (Molded) | | **Package Size** | ~8.0 x 8.0 mm (approximate series size) | | **Mounting Type** | Surface Mount Device (SMD/SMT) | | **Shielding** | Magnetically Shielded (Low EMI) | --- ## Key Components & Construction ### 1. The Core Material The "PW" series typically utilizes a **metal alloy powder core**. Unlike traditional ferrite cores, these are molded around the wire under high pressure. This results in: * **Soft Saturation:** The inductance doesn't drop off abruptly when current increases. * **High Current Handling:** Higher saturation current ($I_{sat}$) compared to ferrite. ### 2. The Coil (Winding) It features a flat or round copper wire winding. The use of flat wire in some versions reduces **DC Resistance (DCR)**, which minimizes energy loss as heat and increases efficiency. ### 3. Magnetic Shielding Because the core material completely surrounds the winding, the component is inherently shielded. This prevents electromagnetic interference (EMI) from leaking out and affecting sensitive nearby components like CPUs or RF modules. --- ## Typical Applications Due to its low inductance (0.47 µH) and high current capability, this part is commonly found in: * **Voltage Regulator Modules (VRM):** Specifically for modern GPUs and CPUs. * **Point-of-Load (POL) Converters:** Converting a higher rail (e.g., 12V) to a lower rail (e.g., 1.0V). * **High-frequency DC-DC Converters:** Where fast switching speeds are required. * **Battery Powered Devices:** Where efficiency and small footprint are critical. --- ## Part Number Breakdown While manufacturer codes vary slightly, the breakdown usually follows this logic: * **L817:** The series/physical dimension code. * **PW:** Product series type (often denoting high power/molded). * **R47:** Inductance value ($0.47 \times 10^0$ µH). * **M:** Tolerance (±20%). * **F:** Lead-free / RoHS compliant designation.