## SD25-4R7-R Electronic Component Overview The **SD25-4R7-R** is a high-power density, low-profile, shielded drum core inductor manufactured by **Eaton (formerly Cooper Bussmann)**. It belongs to the SD 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)** | 0.0402 Ω (Max) | | **Saturation Current ($I_{sat}$)** | 2.18 A | | **RMS Current ($I_{rms}$)** | 2.30 A | | **Self-Resonant Frequency** | ~43 MHz | | **Operating Temperature** | -40°C to +125°C | --- ### 2. Component Construction and Design The SD25-4R7-R is built using specific materials and geometries to optimize performance in power circuits: * **Shielded Drum Core:** The "shielded" nature means the magnetic flux is largely contained within the component. This reduces **Electromagnetic Interference (EMI)**, making it ideal for densely packed circuit boards. * **Ferrite Material:** The core is made of ferrite, which provides high permeability and low core losses at high frequencies. * **Surface Mount Device (SMD):** Designed for automated pick-and-place assembly with a robust solder pad construction. --- ### 3. Part Number Breakdown Understanding the nomenclature helps in identifying variations: | Segment | Meaning | | :--- | :--- | | **SD** | Series Name (Shielded Drum Core) | | **25** | Physical Size (approx. 5.2mm x 5.2mm x 2.5mm) | | **4R7** | Inductance Value (4.7 microhenries) | | **-R** | RoHS Compliant / Lead-Free | --- ### 4. Typical Applications This component is commonly found in DC-DC converters and power management modules for: * **Mobile Devices:** Smartphones, tablets, and wearables. * **Computing:** Hard disk drives (HDDs) and notebook power rails. * **Consumer Electronics:** Digital cameras and portable media players. * **Industrial:** Small-scale buck/boost converters for sensors. --- ### 5. Footprint (Mechanical Dimensions) ```text Approximate Dimensions: Length: 5.20 mm Width: 5.20 mm Height: 2.50 mm (Max) ```