The **L815PW-R47MF** is a high-performance, surface-mount (SMD) power inductor commonly used in DC-DC converter circuits. It belongs to the category of **molded power inductors**, which are known for their high current density and low acoustic noise. --- ### 1. Part Number Breakdown While naming conventions vary slightly by manufacturer (often associated with brands like **Mag.Layers** or **Chilisin**), the code generally follows this structure: | Segment | Meaning | Details | | :--- | :--- | :--- | | **L815** | Series/Size | Refers to the physical dimensions (approx. 8.0 x 8.0 x 4.0 mm). | | **PW** | Type | Molded Powder/Power type for high current applications. | | **R47** | Inductance | **0.47 µH** (Microhenries). | | **M** | Tolerance | **±20%** (Industry standard for inductors). | | **F** | RoHS/Lead-Free | Indicates compliance with environmental standards. | --- ### 2. Technical Specifications The following values are typical for an 8x8mm 0.47µH molded inductor: | Parameter | Typical Value | | :--- | :--- | | **Inductance** | 0.47 µH | | **DC Resistance (DCR)** | ~1.5 to 2.5 mΩ (Max) | | **Saturation Current ($I_{sat}$)** | ~25A to 35A (Where inductance drops 30%) | | **Heat Rating Current ($I_{rms}$)** | ~15A to 20A (Temperature rise of 40°C) | | **Operating Temperature** | -40°C to +125°C | --- ### 3. Key Electronic Characteristics #### A. Molded Construction The coil is embedded in a metallic magnetic powder (typically an iron alloy). This construction provides: * **Magnetic Shielding:** Minimizes Electromagnetic Interference (EMI) with surrounding components. * **Physical Durability:** Highly resistant to mechanical shock and vibration. * **Soft Saturation:** Unlike ferrite core inductors that lose inductance sharply, this part loses inductance gradually as current increases. #### B. Low DCR (DC Resistance) The "R47" (low inductance) combined with the large physical size allows for thick copper windings. This results in extremely low resistance, minimizing power loss and heat generation during high-current operation. #### C. High Frequency Stability Designed to operate efficiently in switching power supplies with frequencies ranging from **100 kHz to over 1 MHz**. --- ### 4. Common Applications * **Voltage Regulator Modules (VRMs):** Found on PC motherboards and servers. * **GPU/CPU Power Supply:** Used for high-current "Point of Load" (POL) converters. * **Automotive Electronics:** Infotainment systems and ADAS modules (if AEC-Q200 qualified). * **DC-DC Converters:** Buck, Boost, and Sepic converters in telecommunications.