The **MPI4040R4-3R3-R** is a high-performance, power inductor manufactured by **Eaton (formerly Bussmann)**. It belongs to the MPI4040 series, which is designed for high-density power applications such as DC-DC converters and voltage regulator modules (VRMs). --- ### 1. Technical Specifications The following table summarizes the key electrical and physical characteristics of this component: | Parameter | Specification | | :--- | :--- | | **Inductance** | 3.3 µH | | **Tolerance** | ±20% | | **Current Rating (Irms)** | 4.3 A | | **Saturation Current (Isat)** | 5.8 A | | **DC Resistance (DCR)** | 35 mΩ (Typical) | | **Operating Temperature** | -40°C to +125°C | | **Package Size** | 4.7mm x 4.06mm x 4.0mm | | **Construction** | Metal Composite (Shielded) | --- ### 2. Part Number Breakdown Understanding the nomenclature helps in identifying variants within the series: * **MPI**: Series prefix (Metal Powder Inductor). * **4040**: Dimensions (approx. 4.0mm x 4.0mm footprint). * **R4**: Height/Version indicator (4.0mm max height). * **3R3**: Inductance value (3.3 µH; "R" acts as the decimal point). * **-R**: RoHS compliant. --- ### 3. Key Features & Materials * **Metal Composite Core:** This material allows for "soft saturation," meaning the inductance decreases gradually as current increases, rather than dropping off sharply like traditional ferrite cores. * **Magnetically Shielded:** The molded construction minimizes Electromagnetic Interference (EMI), which is critical for sensitive electronics and mobile devices. * **High Current Density:** Designed to handle high peak currents in a very small PCB footprint. * **Low Core Loss:** Optimized for high-frequency switching power supplies (typically up to several MHz). --- ### 4. Typical Applications This inductor is commonly found in: 1. **Mobile Devices:** Smartphones, tablets, and handheld consoles. 2. **Computing:** Laptops, SSD power rails, and server modules. 3. **DC-DC Converters:** Point-of-load (POL) modules where space is constrained but high efficiency is required. 4. **Battery Powered Systems:** Where low DCR is necessary to maximize battery life. --- ### 5. Footprint Example (Recommended Land Pattern) ```markdown [ 1.5mm ] [ 1.5mm ] +-------+ +-------+ | | | | | Pad | | Pad | [ 4.5mm High ] | 1 | | 2 | | | | | +-------+ +-------+ <--- 1.1mm Gap ---> ```