The **DR124-390-R** is a specific model of power inductor manufactured by **Eaton** (formerly Cooper Bussmann/Coiltronics). It is part of the DR series, known for its high power density and shielded construction. --- ### 1. Key Technical Specifications The part number "390" indicates the inductance value, while the "R" signifies RoHS compliance. | Parameter | Specification | | :--- | :--- | | **Inductance** | 39.0 µH (Microhenries) | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | ~0.118 Ω (Typical) | | **Rated Current (Irms)** | 2.25 A (Amperes) | | **Saturation Current (Isat)** | 2.65 A (Amperes) | | **Operating Temperature** | -40°C to +125°C | | **Mounting Type** | Surface Mount (SMD/SMT) | --- ### 2. Physical Characteristics The DR124 series is designed for durability and efficiency in a compact form factor. * **Shielding:** It is a **magnetically shielded** inductor. This is crucial for minimizing Electromagnetic Interference (EMI) with surrounding components. * **Core Material:** Typically utilizes a ferrite core for low core losses at high frequencies. * **Dimensions:** * **Length/Width:** ~12.5 mm x 12.5 mm * **Height:** ~4.5 mm (The "124" suffix usually denotes these dimensions). --- ### 3. Common Applications This component is primarily used in power management circuits where energy storage and filtering are required. 1. **DC-DC Converters:** Used in buck, boost, and SEPIC topologies to regulate voltage. 2. **Computer Peripherals:** Found in laptops, servers, and high-end graphics cards for local power regulation. 3. **Industrial Electronics:** Used in battery-powered equipment and LED drivers. 4. **Telecommunications:** Integral to base station power supplies and networking hardware. --- ### 4. Part Number Breakdown Understanding the Eaton nomenclature helps in identifying similar parts: ```text DR 124 - 390 - R | | | | | | | +-- RoHS Compliant | | +------- Inductance Code: 39 + 0 zeros = 39µH | +------------- Size/Series Identifier (12.5 x 12.5 x 4.5 mm) +---------------- Drum Core / Shielded Series ``` ---