### Overview of the SD52-3R5-R The **SD52-3R5-R** is a high-power density, shielded drum core surface mount (SMD) inductor. It is part of the SD52 series manufactured by **Eaton (formerly Coiltronics/Bussmann)**. These inductors are primarily designed for applications requiring high efficiency and a small footprint. --- ### Technical Specifications The following table highlights the critical electrical and physical characteristics of the SD52-3R5-R: | Parameter | Specification | | :--- | :--- | | **Inductance** | 3.5 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 0.0305 Ω (Typical) | | **Saturation Current ($I_{sat}$)** | 2.16 A (Current at 30% drop in inductance) | | **RMS Current ($I_{rms}$)** | 2.41 A (Current for 40°C temperature rise) | | **Shielding** | Ferrite Shielded (Low EMI) | | **Operating Temperature** | -40°C to +125°C | | **Package Size** | 5.2mm x 5.2mm x 2.0mm | --- ### Key Internal Components & Materials 1. **Ferrite Core:** The "Drum Core" design uses a high-permeability ferrite material to store energy in the form of a magnetic field. 2. **Magnetic Shielding:** The assembly includes a ferrite sleeve or coating that contains the magnetic flux. This minimizes Electromagnetic Interference (EMI) with surrounding components. 3. **Copper Winding:** Precision-wound copper wire determines the inductance and the resistance (DCR). 4. **Terminations:** The base features matte tin-plated over copper pads for reliable surface mount soldering. --- ### Common Applications Due to its low profile (2.0mm height) and shielded nature, the SD52-3R5-R is commonly found in: * **DC-DC Converters:** Buck, Boost, and SEPIC topologies. * **Consumer Electronics:** Laptops, tablets, and handheld GPS units. * **Power Management:** Used in battery-powered devices to regulate voltage with minimal energy loss. * **Noise Filtering:** Acting as a low-pass filter to smooth out current ripples. --- ### Footprint Diagram (Approximate) ```text 5.2mm +-----------+ | | | (O) | 2.0mm High | | +-----------+ [Pad] [Pad] ```