The **DR74-102-R** is a specific model of power inductor manufactured by **Eaton** (formerly Cooper Bussmann/Coiltronics). It belongs to the **DR Series**, which are high-power density, shielded drum core inductors. --- ## 1. Technical Specifications The part number "102" indicates its inductance value, and the "R" indicates RoHS compliance. | Feature | Specification | | :--- | :--- | | **Inductance** | 1000 µH (1.0 mH) | | **Tolerance** | ±20% | | **Current Rating (Irms)** | 0.32 Amps (Approx.) | | **Saturation Current (Isat)** | 0.38 Amps (Approx.) | | **DC Resistance (DCR)** | 1.82 Ω (Max) | | **Operating Temperature** | -40°C to +125°C | | **Package / Case** | 7.6mm x 7.6mm x 4.35mm | | **Shielding** | Magnetically Shielded | --- ## 2. Key Characteristics ### A. Magnetic Shielding The DR74 series is **magnetically shielded**. This is a critical feature for high-density PCB designs because it minimizes Electromagnetic Interference (EMI). It prevents the inductor's magnetic field from affecting nearby sensitive components like microcontrollers or sensors. ### B. Construction * **Core Material:** Ferrite drum core. * **Mounting:** Surface Mount Device (SMD). * **Inductance Range:** The "74" in the name refers to the physical size (approx. 7.6mm square by 4.4mm height). ### C. Saturation Current (Isat) vs. RMS Current (Irms) * **Isat (0.38A):** The point where the inductance drops by a specified percentage (usually 30%) due to magnetic saturation. * **Irms (0.32A):** The continuous current that causes a specific temperature rise (usually 40°C) above ambient. --- ## 3. Common Applications Due to its high inductance (1000µH) and compact size, the DR74-102-R is typically used in: 1. **DC-DC Converters:** Specifically Buck, Boost, and SEPIC topologies. 2. **LED Drivers:** Providing constant current for lighting applications. 3. **Noise Filtering:** Used in input/output filters to smooth voltage ripples. 4. **Computer Peripherals:** Used in laptops, servers, and telecommunications equipment. --- ## 4. Part Number Breakdown ```text DR 74 - 102 - R | | | | | | | +-- RoHS Compliant | | +------- Inductance Code: 10 + 2 zeros = 1000 µH | +------------ Size Code (approx 7.6 x 7.6 x 4.35 mm) +--------------- Series Name (Dual Winding/Drum Core) ```