The **SD12-331-R** is a high-power density, low-profile power inductor manufactured by **Eaton (formerly Coiltronics)**. It is part of the SD12 series, which is designed for applications requiring compact footprints and high efficiency. --- ## 1. Technical Specifications The following table summarizes the key electrical and physical characteristics of the SD12-331-R: | Parameter | Specification | | :--- | :--- | | **Inductance** | 330 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 3.53 Ω (Typical) | | **Saturation Current ($I_{sat}$)** | 0.176 Amperes | | **RMS Current ($I_{rms}$)** | 0.198 Amperes | | **Package / Case** | 5.2mm x 5.2mm x 1.2mm | | **Core Material** | Ferrite | | **Shielding** | Shielded (Magnetic) | --- ## 2. Key Features * **Low Profile:** With a height of only 1.2mm, it is ideal for ultra-thin electronic devices. * **Magnetic Shielding:** The component is shielded to minimize Electromagnetic Interference (EMI), which is critical for densely packed circuit boards. * **Ferrite Core:** Ensures low core losses at high switching frequencies. * **RoHS Compliant:** The "-R" suffix indicates that the part is lead-free and meets RoHS environmental standards. --- ## 3. Common Applications Due to its high inductance (330 µH) and small form factor, it is typically used in the following scenarios: 1. **DC-DC Converters:** Used as an energy storage element in buck, boost, or buck-boost regulators. 2. **Portable Electronics:** Found in smartphones, tablets, and wearables where PCB vertical space is limited. 3. **LED Drivers:** Provides current smoothing for LED lighting circuits. 4. **Battery Powered Filters:** Used for noise decoupling in low-power handheld devices. --- ## 4. Typical Footprint and Marking The part utilizes a surface-mount (SMD) landing pattern. The top of the component usually features a code representing the inductance value: * **Marking:** `331` * `33` = First two significant digits. * `1` = Number of zeros following (Multiplier). * Calculation: $33 \times 10^1 = 330$ µH.