### Technical Overview of the SD12-1R2-R The **SD12-1R2-R** is a high-power density, low-profile power inductor manufactured by **Eaton (formerly 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** | 1.2 µH | | **Tolerance** | ±20% | | **Current Rating (Irms)** | 2.58 Amps (Typical) | | **Saturation Current (Isat)** | 3.65 Amps (Typical) | | **DC Resistance (DCR)** | 39.1 mΩ (Typical) | | **Operating Temperature** | -40°C to +125°C | | **Package / Case** | 5.2mm x 5.2mm x 1.2mm | --- ### 2. Physical Construction The "SD12" designation refers to the physical dimensions and construction style: * **Shielded Construction:** The inductor is magnetically shielded. This is critical for high-density PCB designs as it minimizes Electromagnetic Interference (EMI) with surrounding components. * **Low Profile:** The "12" in the part number indicates a maximum height of **1.2 mm**, making it ideal for ultra-thin electronics like smartphones and tablets. * **Ferrite Core:** Utilizes a ferrite core material that provides low core losses at high frequencies. --- ### 3. Part Number Breakdown Understanding the nomenclature helps identify variations in the series: | Segment | Meaning | | :--- | :--- | | **SD** | Series Name (Shielded Drum Inductor) | | **12** | Dimensional Code (Approx. 1.2mm height) | | **1R2** | Inductance Value (1.2 microhenries) | | **-R** | RoHS Compliant / Lead-Free | --- ### 4. Applications Due to its balance of small size and high current handling, the SD12-1R2-R is commonly used in: * **DC-DC Converters:** Buck, boost, and buck-boost regulators. * **Mobile Devices:** Power management modules in smartphones and wearables. * **Computer Peripherals:** SSDs, laptop motherboards, and graphic cards. * **Battery Powered Systems:** Where high efficiency and low DCR (Direct Current Resistance) are required to prolong battery life. --- ### 5. Critical Performance Factors * **Saturation Current (Isat):** This is the point where the inductance drops by a specified percentage (usually 30%). For the 1R2 model, it handles up to 3.65A before the magnetic core saturates. * **Heating Current (Irms):** This refers to the continuous DC current that causes a 40°C temperature rise. Designing within this limit is essential for long-term component reliability.