The **SD20-820-R** is a specific model of surface-mount (SMD) power inductor manufactured by **Eaton (formerly Cooper Bussmann)**. It belongs to the SD20 series, which is known for its low profile and high power density. --- ### 1. General Specifications Below are the primary electrical and physical characteristics of the SD20-820-R: | Parameter | Value | | :--- | :--- | | **Inductance** | 82.0 µH | | **Tolerance** | ±20% | | **Rated Current ($I_{rms}$)** | 0.448 Amperes (Typical) | | **Saturation Current ($I_{sat}$)** | 0.471 Amperes (Typical) | | **DC Resistance (DCR)** | 0.814 Ohms (Max) | | **Shielding** | Magnetically Shielded | | **Operating Temperature** | -40°C to +125°C | --- ### 2. Part Number Breakdown Understanding the nomenclature helps in identifying variations of the component: * **SD**: Product Series (Shielded Drum Core). * **20**: Size code (refers to the physical footprint, approx. 5.2mm x 5.2mm). * **820**: Inductance value in microhenries (82 followed by zero additional zeros = 82µH). * **R**: RoHS compliant. --- ### 3. Key Electronic Features * **Magnetic Shielding:** The inductor is enclosed in a ferrite housing. This minimizes Electromagnetic Interference (EMI), preventing the inductor's magnetic field from affecting nearby sensitive components on the PCB. * **High Power Density:** Designed to handle significant current relative to its small 2.0mm height profile. * **Ferrite Core Material:** Ensures low core losses, making it efficient for high-frequency switching applications. --- ### 4. Common Applications The SD20-820-R is typically found in power management circuits where space is limited: 1. **DC-DC Converters:** Used in buck, boost, and SEPIC topologies. 2. **Portable Electronics:** Smartphones, tablets, and handheld GPS units. 3. **Computer Peripherals:** Hard disk drives and solid-state drives. 4. **Battery Powered Equipment:** Due to its high efficiency and low DCR. --- ### 5. Design Considerations * **Saturation Current:** When designing, ensure the peak circuit current does not exceed the $I_{sat}$ (0.471A). Exceeding this will cause the inductance to drop sharply. * **Thermal Management:** The $I_{rms}$ rating is based on a temperature rise (usually 40°C) above ambient. Ensure adequate airflow or copper traces to dissipate heat.