## Technical Overview: DRA124-3R3-R Inductor The **DRA124-3R3-R** is a high-power, shielded drum core inductor manufactured by **Eaton (formerly Bussmann/Coiltronics)**. It is specifically designed for automotive applications and high-density power conversion. --- ### 1. Key Technical Specifications | Parameter | Value | | :--- | :--- | | **Inductance** | 3.3 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 11.5 mΩ (Nominal) | | **Saturation Current ($I_{sat}$)** | 13.9 A | | **RMS Current ($I_{rms}$)** | 9.15 A | | **Operating Temperature** | -40°C to +165°C | | **Package / Case** | 12.5mm x 12.5mm x 4.5mm | --- ### 2. Physical Construction and Design * **Shielding:** It features a magnetic shield, which minimizes Electromagnetic Interference (EMI) and prevents the magnetic field from affecting nearby sensitive components. * **Core Material:** Ferrite drum core, which provides high efficiency and low core losses. * **Terminations:** Matte tin-plated lead-free terminations over copper, suitable for standard SMT (Surface Mount Technology) reflow soldering. * **Automotive Grade:** It is **AEC-Q200 Grade 1 qualified**, meaning it can withstand the mechanical and thermal stresses of automotive environments. --- ### 3. Common Applications Due to its high current handling and thermal stability, this part is used in: 1. **Automotive Electronics:** Power steering, engine control units (ECU), and lighting. 2. **DC-DC Converters:** Buck, boost, and forward converters. 3. **Industrial Controls:** High-temperature power supplies and motor drivers. 4. **Computing:** Voltage Regulator Modules (VRM) for servers and workstations. --- ### 4. Part Number Breakdown The part number follows a specific nomenclature: * **DRA**: Series name (Automotive High Power, Shielded) * **124**: Physical dimensions (~12.5mm x 4.5mm) * **3R3**: Inductance value (3.3 µH; "R" acts as the decimal point) * **-R**: RoHS Compliant / Lead-free ---