The **SD12-820-R** is a high-power density, low-profile power inductor manufactured by **Eaton (formerly Coiltronics/Bussmann)**. It belongs to the SD12 series, which is characterized by its shielded drum core construction and surface-mount (SMD) design. --- ### 1. Key Technical Specifications Below are the primary electrical and physical characteristics of the SD12-820-R: | Parameter | Value | | :--- | :--- | | **Inductance** | 82.0 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 1.48 Ω (Typical) | | **Saturation Current ($I_{sat}$)** | 0.322 Amperes | | **RMS Current ($I_{rms}$)** | 0.413 Amperes | | **Operating Temperature** | -40°C to +125°C | | **Package / Case** | 5.2mm x 5.2mm x 1.2mm | --- ### 2. Physical Composition * **Core Material:** Ferrite. This allows for high efficiency and low core losses at high frequencies. * **Shielding:** It is **magnetically shielded**. This is a critical feature that minimizes Electromagnetic Interference (EMI), allowing the component to be placed near sensitive circuitry without causing noise issues. * **Termination:** Lead-free, RoHS compliant matte tin over copper. ### 3. Application Use Cases The SD12-820-R is primarily used in power management circuits where vertical space is limited. Common applications include: 1. **DC-DC Converters:** Used as an energy storage element in buck (step-down) or boost (step-up) converters. 2. **Portable Electronics:** Ideal for mobile phones, digital cameras, and media players due to its 1.2mm ultra-low profile. 3. **Battery Powered Systems:** Used in handheld instruments where high efficiency and small footprint are required. 4. **Computer Peripherals:** Found in EL backlighting and small LED drivers. --- ### 4. Interpretation of the Part Number * **SD:** Series name (Shielded Drum). * **12:** Dimensional code (approx. 1.2mm height). * **820:** Inductance value in Microhenries (82 followed by zero zeros = 82µH). * **R:** RoHS compliant.