The **SD3112-2R2-R** is a high-power density, low-profile shielded drum core inductor manufactured by **Eaton (formerly Cooper Bussmann/Coiltronics)**. It is part of the SD3112 series, designed specifically for applications where space is at a premium and electromagnetic interference (EMI) must be minimized. --- ### ## Technical Specifications The following table outlines the primary electrical and physical characteristics of the SD3112-2R2-R: | Parameter | Specification | | :--- | :--- | | **Inductance** | 2.2 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 0.115 Ω (Typical) | | **Saturation Current ($I_{sat}$)** | 1.15 A | | **RMS Current ($I_{rms}$)** | 1.12 A | | **Shielding** | Ferrite Shielded | | **Dimensions** | 3.1mm x 3.1mm x 1.2mm | | **Operating Temperature** | -40°C to +125°C | --- ### ## Component Breakdown #### 1. Magnetic Shielding The "SD" in the part number stands for **Shielded Drum**. The inductor features a ferrite sleeve that wraps around the core. This construction confines the magnetic flux within the component, which: * Reduces EMI (Electromagnetic Interference) with neighboring components. * Protects the inductor from external magnetic fields. #### 2. Core Material It utilizes a **Ferrite core**, which provides high efficiency and low core losses at high frequencies. This makes it ideal for modern switching power supplies that operate in the MHz range. #### 3. Low Profile Design The "12" in the suffix refers to the maximum height (1.2mm). This ultra-thin form factor is essential for: * Mobile phones and handheld devices. * Wearable electronics. * Ultra-thin laptops (Ultrabooks). --- ### ## Applications The SD3112-2R2-R is commonly found in the following electronic circuits: * **DC-DC Converters:** Buck, Boost, and SEPIC topologies. * **LED Drivers:** Providing constant current for backlighting. * **Battery Powered Devices:** Where high efficiency is required to extend battery life. * **Noise Filtering:** Acting as a low-pass filter in signal lines. --- ### ## Part Number Decoder `SD3112 - 2R2 - R` * **SD3112:** Series name (3.1 x 3.1 x 1.2 mm size). * **2R2:** Inductance value. The "R" acts as a decimal point ($2.2$ µH). * **-R:** Indicates the product is RoHS compliant.