The **DR1040-8R2-R** is a specific model of power inductor manufactured by Eaton (formerly Cooper Bussmann). It belongs to the DR series, which is known for its high power density and shielded construction. --- ## 1. Component Overview The part number can be broken down to understand its physical and electrical characteristics: | Part Segment | Meaning | Details | | :--- | :--- | :--- | | **DR1040** | Series/Size | 10.5mm x 10.3mm footprint; 4.0mm height | | **8R2** | Inductance Value | 8.2 microhenries (µH) | | **-R** | RoHS Compliant | Lead-free and environmentally compliant | --- ## 2. Technical Specifications This component is designed for DC-DC converters and power supply filtering. Below are the typical electrical parameters for the 8R2 variant: ### Electrical Profile * **Inductance:** 8.2 µH (Measured at 100 kHz, 0.1 Vrms) * **Rated Current (Irms):** Approximately 3.52 Amps (Current causing a 40°C temperature rise) * **Saturation Current (Isat):** Approximately 4.16 Amps (Current causing a 30% drop in inductance) * **DC Resistance (DCR):** Typically ~31.0 mΩ (milliohms) * **Operating Temperature:** -40°C to +125°C --- ## 3. Key Features ### Shielded Construction The inductor is magnetically shielded. This means it has a closed magnetic circuit which results in: * **Low EMI:** Minimal electromagnetic interference with surrounding components. * **High Density:** Allows for components to be placed closer together on a PCB. ### Drum Core Technology The "DR" series utilizes a ferrite drum core with a specialized winding and resin coating, providing a balance between high current handling and small physical volume. --- ## 4. Common Applications Due to its 8.2µH value and ~4A current rating, it is commonly found in: 1. **Buck/Boost Converters:** Used for energy storage in voltage regulation circuits. 2. **Laptops/Tablets:** Powering CPUs and GPUs where space is limited. 3. **LED Drivers:** Providing constant current for lighting applications. 4. **Network Hardware:** Servers and switches requiring stable power rails. ---