The **SD14-681-R** is a specific surface-mount (SMD) power inductor part of the **SD series** manufactured by **Eaton (formerly Cooper Bussmann)**. It is a high-power density, shielded drum core inductor. --- ## 1. Technical Specifications The part number "681" identifies the inductance value, while the "R" indicates RoHS compliance. | Parameter | Specification | | :--- | :--- | | **Inductance** | 680 µH (Microhenries) | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | ~1.85 Ω (Typical) | | **Irms (Current Rating)** | ~0.345 A (345 mA) | | **Isat (Saturation Current)** | ~0.360 A (360 mA) | | **Dimensions** | 5.2mm x 5.2mm x 1.45mm | | **Shielding** | Magnetically Shielded | --- ## 2. Key Electronic Features ### A. Magnetic Shielding The SD14 series is magnetically shielded. This is critical in modern electronics to minimize **Electromagnetic Interference (EMI)**. It prevents the inductor's magnetic field from affecting nearby sensitive components on the PCB. ### B. Low Profile (1.45mm) The "14" in the part number indicates the height (approx. 1.45mm). This makes it ideal for ultra-thin electronics like tablets, smartphones, and wearable devices. ### C. Ferrite Core Construction The drum core is made of ferrite, which provides high efficiency and low core losses at high frequencies. --- ## 3. Typical Applications The SD14-681-R is generally used in power management circuits where voltage conversion is required. * **DC-DC Converters:** Used in Buck (Step-down), Boost (Step-up), and SEPIC topologies. * **LED Drivers:** Providing constant current for backlighting. * **Battery Powered Devices:** Due to its small footprint and efficiency. * **Noise Filtering:** Acting as a choke to smooth out ripples in DC power lines. --- ## 4. Part Number Breakdown Understanding the nomenclature helps in selecting substitutes: 1. **SD**: Series name (Shielded Drum). 2. **14**: Package size/height (approx. 5.2 x 5.2 x 1.45 mm). 3. **681**: Inductance code ($68 \times 10^1 = 680$ µH). 4. **R**: RoHS compliant / Lead-free. ---