## SD12-4R7-R: Electronic Component Analysis The **SD12-4R7-R** is a high-power density, low-profile power inductor manufactured by **Eaton (formerly Cooper Bussmann)**. It belongs to the SD12 series, which is designed for applications requiring compact footprints and high efficiency. --- ### 1. Key Technical Specifications | Parameter | Value | | :--- | :--- | | **Inductance** | 4.7 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 0.119 Ω (Typical) | | **Saturation Current ($I_{sat}$)** | 1.34 Amperes | | **RMS Current ($I_{rms}$)** | 1.15 Amperes | | **Operating Temperature** | -40°C to +125°C | | **Dimensions** | 5.2mm x 5.2mm x 1.2mm | | **Shielding** | Ferrite Drum Core (Shielded) | --- ### 2. Physical Characteristics * **Form Factor:** Surface Mount Device (SMD). * **Construction:** It features a magnetic shielding structure which minimizes Electromagnetic Interference (EMI), making it suitable for densely packed circuit boards. * **Low Profile:** With a height of only 1.2mm, it is ideal for "thin" electronics like smartphones, tablets, and wearable tech. --- ### 3. Part Number Breakdown The nomenclature follows a specific logic: * **SD12:** The series identifier (Standard Inductor, 1.2mm height). * **4R7:** The inductance value. "R" acts as the decimal point (4.7 microhenries). * **R:** Indicates compliance with RoHS (Lead-free) standards. --- ### 4. Common Applications Due to its balance of size and current handling, the SD12-4R7-R is frequently used in: 1. **DC-DC Converters:** Specifically Buck, Boost, and SEPIC topologies. 2. **Portable Devices:** Handheld GPS, Media Players, and Digital Cameras. 3. **Computing:** Battery-powered peripherals and VRM (Voltage Regulator Module) circuits. 4. **LED Drivers:** Small-scale lighting circuits. --- ### 5. Footprint (Top View Representation) ```text 5.2mm +-----------+ | | | 4R7 | 5.2mm | | +-----------+ (SMD) ```