The **SD3812-R47-R** is a high-performance, low-profile power inductor manufactured by Eaton (formerly Bussmann). It is part of the SD3812 series, designed specifically for applications where space is limited and high efficiency is required. --- ### 1. Key Technical Specifications The part number follows a specific nomenclature that defines its electronic characteristics: | Parameter | Value / Description | | :--- | :--- | | **Inductance** | 0.47 µH | | **Tolerance** | ±20% | | **Current Rating (Irms)** | 2.51 Amps | | **Saturation Current (Isat)** | 3.5 Amps | | **DC Resistance (DCR)** | 48 mΩ (Max) | | **Operating Temperature** | -40°C to +125°C | | **Dimensions** | 4.0mm x 4.0mm x 1.2mm | --- ### 2. Physical & Material Construction * **Shielding:** This is a **shielded** inductor. It uses a ferrite drum core with a ferrite sleeve (ferrite-based magnetic shielding) to minimize Electromagnetic Interference (EMI) with surrounding components. * **Form Factor:** It is a Surface Mount Device (SMD). The "12" in the part number indicates the height (approx. 1.2mm), making it ideal for ultra-thin electronics like smartphones or tablets. * **Terminations:** Lead-free and RoHS compliant, typically using matte tin over nickel plating. --- ### 3. Functional Role in Circuits The SD3812-R47-R is primarily used in **DC-DC Converters**. Because of its low inductance (0.47 µH), it is optimized for high-frequency switching. * **Energy Storage:** Stores energy in its magnetic field during the "on" cycle of a buck or boost converter. * **Filtering:** Smooths out the output current ripple to provide a steady voltage to sensitive integrated circuits (ICs). * **Efficiency:** The low DCR (Direct Current Resistance) ensures minimal power loss through heat, which is critical for battery-operated devices. --- ### 4. Common Applications * **Mobile Electronics:** Smartphones, wearables, and handheld GPS units. * **Computing:** Solid State Drives (SSDs) and ultra-books. * **IoT Devices:** Small sensor nodes requiring efficient power management in a tiny footprint. ---