### MPI4040R3-1R2-R: Component Overview The **MPI4040R3-1R2-R** is a high-current, low-profile power inductor manufactured by **Eaton (formerly Coiltronics)**. It belongs to the MPI4040 series, which is characterized by its molded construction and high power density. --- ### Technical Specifications | Parameter | Value | | :--- | :--- | | **Inductance** | 1.2 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 14.5 mΩ (typical) / 17.5 mΩ (max) | | **Rated Current (Irms)** | 7.7 A | | **Saturation Current (Isat)** | 13.0 A | | **Operating Temperature** | -40°C to +125°C | | **Package Size** | 4.7mm x 4.06mm x 3.0mm | --- ### Key Features and Construction 1. **Molded Construction:** The inductor uses a metal powder core technology. The wire is wound and then molded into a composite iron powder body. This design provides excellent magnetic shielding and reduces EMI (Electromagnetic Interference). 2. **Soft Saturation:** Unlike ferrite inductors that have a sharp drop in inductance when current limits are exceeded, this part has a "soft saturation" curve. This makes the circuit more stable during transient current spikes. 3. **High Current Density:** Its compact 4040 footprint (4.0mm x 4.0mm approx.) allows for significant current handling (up to 7.7A continuous) in space-constrained applications. 4. **Low DCR:** The low DC resistance minimizes power loss through heat, increasing the overall efficiency of power conversion. --- ### Common Applications * **DC-DC Converters:** Used as the main energy storage element in buck, boost, or buck-boost regulators. * **Mobile Electronics:** Ideal for smartphones, tablets, and handheld devices due to its low profile (3mm height). * **Computing:** Used in VRM (Voltage Regulator Modules) for CPUs and GPUs. * **Distributed Power Systems:** Integrated into Point-of-Load (POL) converters. --- ### Part Number Breakdown | Segment | Meaning | | :--- | :--- | | **MPI** | Series Name (Molded Power Inductor) | | **4040** | Package Size (approx. 4.0mm x 4.0mm) | | **R3** | Product Revision / Height Code (3.0mm max) | | **1R2** | Inductance Value (1.2 µH) | | **-R** | RoHS Compliant |