## Technical Overview of UP2B-821-R The **UP2B-821-R** is a high-performance, shielded power inductor manufactured by **Eaton (formerly Coiltronics/Bussmann)**. It belongs to the Uni-Pac (UP) series, specifically designed for surface-mount applications requiring high energy storage and low electromagnetic interference (EMI). ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Inductance** | 820 µH (Microhenries) | | **Tolerance** | ±20% | | **Current Rating (Irms)** | 0.358 Amps | | **Saturation Current (Isat)** | 0.380 Amps | | **DC Resistance (DCR)** | 1.636 Ohms (Max) | | **Operating Temperature** | -40°C to +125°C | | **Package / Case** | Non-standard SMD (approx. 13.9mm x 9.4mm) | | **Shielding** | Ferrite Core (Shielded) | --- ### 2. Physical Construction and Components The component is built using several specific electronic materials and engineering techniques: * **Ferrite Drum Core:** The "brain" of the inductor, providing high magnetic permeability to store energy efficiently in a small footprint. * **Magnetic Shielding:** The assembly is encapsulated in a magnetic material. This minimizes **EMI (Electromagnetic Interference)**, ensuring that the inductor's magnetic field does not interfere with nearby sensitive components on the PCB. * **Copper Winding:** High-purity copper wire is wound around the core. The thickness and number of turns determine the 820 µH inductance and the DC resistance. * **Lead-Free Terminations:** The "-R" suffix indicates that the part is **RoHS compliant**, utilizing lead-free solder finishes for environmental safety. --- ### 3. Common Applications Due to its high inductance value (820 µH), this part is typically used in low-current, high-voltage, or high-impedance filtering scenarios: 1. **DC-DC Converters:** Used as an energy storage element in buck, boost, or SEPIC converters. 2. **Noise Filtering:** Excellent for power line filtering to remove high-frequency noise from switching power supplies. 3. **LED Drivers:** Used in constant-current circuits for lighting. 4. **Industrial Electronics:** Found in PLCs and sensors where stable power delivery is critical. --- ### 4. Part Number Breakdown * **UP2B**: The series designation (Size 2B dimensions). * **821**: The Inductance code. The first two digits (82) are the value, and the third (1) is the multiplier (10^1). So, $82 \times 10^1 = 820$ µH. * **-R**: Indicates RoHS compliance. ---