The **UP2B-681-R** is a high-performance power inductor manufactured by **Eaton (formerly Cooper Bussmann/Coiltronics)**. It belongs to the Uni-Pac (UP) series, specifically designed for surface mount (SMD) applications requiring high power density. --- ### 1. Key Technical Specifications The part number "681" indicates the inductance value, while the "R" signifies RoHS compliance. | Parameter | Specification | | :--- | :--- | | **Inductance** | 680 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 1.130 Ω (Max) | | **Saturation Current ($I_{sat}$)** | 0.51 Amps | | **RMS Current ($I_{rms}$)** | 0.55 Amps | | **Operating Temperature** | -40°C to +125°C | | **Package Type** | Surface Mount (SMD) | --- ### 2. Physical Construction The UP2B series is known for its robust drum core construction: * **Core Material:** Ferrite core which provides low core losses. * **Shielding:** This specific series is **non-shielded**, meaning it offers higher saturation currents for its size but may emit more electromagnetic interference (EMI) than shielded alternatives. * **Dimensions:** Approximately $13.97 \text{ mm} \times 9.40 \text{ mm} \times 5.94 \text{ mm}$. --- ### 3. Applications and Usage This component is typically found in power management circuits where high inductance is required to smooth current or store energy. 1. **DC-DC Converters:** Used in buck, boost, and forward converters. 2. **Buck-Boost Regulators:** Ideal for battery-powered devices where voltage needs to be stepped up or down. 3. **Filtering:** Used in input/output filters to reduce ripple and noise in power supplies. 4. **LED Drivers:** Providing constant current for lighting applications. --- ### 4. Part Number Breakdown Understanding the nomenclature helps in identifying similar components in the series: | Segment | Meaning | | :--- | :--- | | **UP2B** | Series identifier (Uni-Pac, Size 2B) | | **681** | Inductance Code ($68 \times 10^1 = 680 \text{ µH}$) | | **R** | RoHS Compliant / Lead-Free | ---