## Overview of SD18-6R2-R The **SD18-6R2-R** is a high-power density, low-profile shielded drum core inductor. It is manufactured by **Eaton (formerly Cooper Bussmann/Coiltronics)** and is widely used in DC-DC converter applications where space is limited and EMI (Electromagnetic Interference) protection is required. --- ### Key Specifications | Parameter | Value | | :--- | :--- | | **Inductance** | 6.2 µH | | **Tolerance** | ±20% | | **Current Rating (Irms)** | 1.84 Amps | | **Saturation Current (Isat)** | 2.11 Amps | | **DC Resistance (DCR)** | 0.0578 Ohms (Typical) | | **Operating Temperature** | -40°C to +125°C | | **Shielding** | Ferrite Shielded | | **Package / Case** | Non-standard SMD (approx. 5.2mm x 5.2mm x 1.8mm) | --- ### Technical Components & Construction #### 1. Magnetic Core (Ferrite Drum) The "SD" in the part number stands for **Shielded Drum**. The inductor uses a ferrite core shaped like a bobbin (drum) which provides high permeability. #### 2. Magnetic Shielding The device features a ferrite sleeve or coating that closes the magnetic loop. This is critical for: * **Reducing EMI:** Preventing magnetic flux from escaping and interfering with nearby components. * **Efficiency:** Minimizing energy loss through stray fields. #### 3. Windings Copper wire is wound around the drum core. The "6R2" in the name indicates the inductance value ($6.2$ microhenries), where "R" acts as the decimal point. #### 4. Termination (R) The suffix "-R" indicates that the part is **RoHS compliant**, meaning it is lead-free and meets environmental safety standards. --- ### Common Applications The SD18 series is specifically designed for high-efficiency power management: * **Mobile Electronics:** Smartphones and tablets due to the 1.8mm low-profile height. * **DC-DC Converters:** Buck, boost, and SEPIC topologies. * **Computer Peripherals:** Hard drives and solid-state drives. * **Battery Powered Tools:** Where high current capability in a small footprint is necessary. --- ### Design Considerations * **Saturation:** Ensure the peak circuit current does not exceed the **Isat (2.11A)**, or the inductance will drop sharply. * **Thermal Management:** The **Irms (1.84A)** rating is based on a specific temperature rise (usually 40°C). Operating above this may damage the component or the PCB.