The **MPI4040R1-R68-R** is a high-performance, shielded power inductor designed by Eaton (formerly Cooper Bussmann). It is part of the MPI4040 series, known for its rugged construction and high current handling in a compact surface-mount package. --- ### 1. Part Number Breakdown Understanding the nomenclature helps identify the component's specific characteristics: | Code Segment | Meaning | Specification | | :--- | :--- | :--- | | **MPI** | Series Name | Molded Power Inductor | | **4040** | Size Code | 4.7mm x 4.06mm (Approx.) | | **R1** | Revision | Revision Level 1 | | **-R68** | Inductance | 0.68 µH (Microhenries) | | **-R** | Compliance | RoHS Compliant | --- ### 2. Key Specifications This inductor is engineered for high-frequency DC-DC converters and power supplies. * **Inductance:** 0.68 µH * **Tolerance:** ±20% * **DCR (Direct Current Resistance):** Very low (typically ~8.4 mΩ) to minimize power loss. * **Isat (Saturation Current):** The current level where inductance drops by a specific percentage (usually 30%). For this part, it is typically around **12A - 15A**. * **Irms (RMS Current):** The continuous current that causes a 40°C temperature rise (typically around **7.5A - 8.5A**). * **Operating Temperature:** -40°C to +125°C. --- ### 3. Construction & Features The "Molded" nature of the MPI series provides several technical advantages: 1. **Magnetic Shielding:** The metal powder molding process results in a self-shielded structure. This significantly reduces Electro-Magnetic Interference (EMI), which is critical for sensitive nearby circuits. 2. **Rugged Design:** The molded construction handles high transient current spikes without hard saturation (it has a "soft" saturation curve). 3. **Low Buzz Noise:** Because the coil is encased in a solid composite, it is less prone to acoustic noise (whining) caused by magnetostriction. --- ### 4. Common Applications Due to its high current density and low profile, it is commonly found in: * **Computing:** Voltage Regulator Modules (VRMs) for CPUs and GPUs. * **Mobile Devices:** High-efficiency power stages in tablets and smartphones. * **Networking:** DC-DC converters for routers and switches. * **Automotive/Industrial:** Distributed power systems where space is limited. --- ### 5. Footprint (Dimensions) The physical footprint is standardized for pick-and-place machines: * **Length:** 4.7 mm (Max) * **Width:** 4.06 mm (Max) * **Height:** 1.2 mm to 2.0 mm (Depending on specific R1 sub-version)