### Overview of SD12-681-R The **SD12-681-R** is a high-power, low-profile SMT (Surface Mount Technology) power inductor manufactured by **Eaton (formerly Bussmann/Coiltronics)**. It is part of the SD12 series, designed for applications requiring high power density and space efficiency. --- ### Technical Specifications | Parameter | Value | | :--- | :--- | | **Inductance** | 680 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 9.07 Ω (Typical) | | **Rated Current ($I_{rms}$)** | 0.138 Amps | | **Saturation Current ($I_{sat}$)** | 0.142 Amps | | **Operating Temperature** | -40°C to +125°C | | **Shielding** | Magnetically Shielded | | **Package Size** | 5.2mm x 5.2mm x 1.2mm | --- ### Key Features and Construction 1. **Magnetic Shielding:** The component is shielded, which minimizes Electromagnetic Interference (EMI). This is critical for dense PCB layouts where components are placed close to sensitive signal lines. 2. **Low Profile:** With a height of only **1.2mm**, it is ideal for ultra-thin electronics like smartphones, wearables, and thin-client laptops. 3. **Ferrite Core Material:** Uses a ferrite core which provides high efficiency and low core losses at switching frequencies. 4. **RoHS Compliant:** The "-R" suffix indicates that the part is fully compliant with RoHS standards (lead-free). --- ### Common Applications The SD12-681-R is typically used in the following power management circuits: * **DC-DC Converters:** Buck, Boost, and SEPIC topologies. * **Battery Powered Devices:** Due to its small footprint and efficiency. * **LED Drivers:** Used to maintain constant current in lighting applications. * **Filter Chokes:** Used in signal lines to suppress high-frequency noise. --- ### Mechanical Drawing Reference (SMT Footprint) ```text [ 5.2mm ] +-------------+ | | | (681) | [ 5.2mm ] | | +-------------+ [1.2mm Height] ```