The **MPI4040R3-4R7-R** is a high-performance, power inductor manufactured by **Eaton (formerly Coiltronics)**. It belongs to the MPI4040 series, which is specifically designed for high-frequency DC-DC converters and power management applications. ### 1. Part Number Breakdown Understanding the nomenclature helps identify the component's specific characteristics: | Code Segment | Meaning | Specification | | :--- | :--- | :--- | | **MPI** | Series Name | Miniature Power Inductor | | **4040** | Package Size | 4.7mm x 4.06mm (Approx.) | | **R3** | Version/Height | 1.85 mm or 2.0 mm (varies by revision) | | **4R7** | Inductance Value | **4.7 µH** | | **R** | RoHS Compliance | Fully RoHS compliant | --- ### 2. Key Technical Specifications The MPI4040R3-4R7-R is characterized by its high current handling and rugged construction. | Parameter | Value | | :--- | :--- | | **Inductance** | 4.7 µH | | **Tolerance** | ±20% | | **Rated Current (Irms)** | ~3.3 A (Typical) | | **Saturation Current (Isat)** | ~4.0 A (Typical) | | **DC Resistance (DCR)** | ~55 mΩ (Typical) | | **Operating Temperature** | -40°C to +125°C | | **Shielding** | Magnetically shielded (low EMI) | --- ### 3. Core Features and Construction * **Molded Construction:** It uses a metal powder core technology. This "molded" design allows for high saturation currents and provides a "soft" saturation characteristic (it doesn't lose inductance instantly when over-current occurs). * **Magnetically Shielded:** The structure naturally contains the magnetic field, which is critical for preventing interference with nearby sensitive components in compact PCB layouts. * **High Efficiency:** Optimized for low DCR (DC resistance) and low core losses at high switching frequencies (up to several MHz). --- ### 4. Common Applications This inductor is typically used in the following circuits: 1. **Buck/Boost Converters:** Used in point-of-load (POL) power supplies for laptops, tablets, and handheld devices. 2. **Battery Powered Systems:** Ideal for mobile devices where space is limited but high current is required. 3. **IoT Devices:** Used in smart home sensors and wearables due to its small footprint. 4. **Distributed Power Systems:** Providing stable voltage rails for FPGAs and microprocessors. --- ### 5. Footprint (Mechanical Data) The component is an SMD (Surface Mount Device) with the following approximate dimensions: * **Length:** 4.7 mm (max) * **Width:** 4.06 mm (max) * **Height:** 1.85 mm to 2.0 mm (low profile)