## Technical Overview of DR73-4R7-R The **DR73-4R7-R** is a high-power, shielded surface-mount (SMD) inductor manufactured by **Eaton (formerly Bussmann/Coiltronics)**. It is part of the DR series, which is known for its high efficiency and rugged construction. --- ### 1. Key Technical Specifications The part number encodes the specific characteristics of the component. Below are the primary electrical and physical specifications: | Parameter | Specification | | :--- | :--- | | **Inductance** | 4.7 µH | | **Tolerance** | ±20% | | **Current Rating (Irms)** | 3.54 Amperes (Typical) | | **Saturation Current (Isat)** | 4.14 Amperes (Typical) | | **DC Resistance (DCR)** | 0.0267 Ohms (Max) | | **Operating Temperature** | -40°C to +125°C | | **Shielding** | Magnetically Shielded | --- ### 2. Physical Construction and Dimensions The "73" in the part number refers to the physical size of the inductor. This series utilizes a ferrite drum core with a ferrite sleeve to minimize EMI (Electromagnetic Interference). * **Footprint:** 7.6mm x 7.6mm * **Height:** 3.55mm (Maximum) * **Mounting Type:** Surface Mount (SMD) * **Core Material:** Ferrite --- ### 3. Part Number Breakdown Understanding the nomenclature helps in identifying similar components within the series: | Segment | Meaning | | :--- | :--- | | **DR** | Series Name (Drum Core, Shielded) | | **73** | Size Code (approx. 7mm x 3mm height) | | **4R7** | Inductance Value (4.7 microhenries; 'R' acts as decimal) | | **-R** | RoHS Compliant | --- ### 4. Typical Applications The DR73-4R7-R is designed for high-density applications where power efficiency and low noise are critical. Common use cases include: * **DC-DC Converters:** Used as a storage element in buck, boost, or buck-boost regulators. * **Computer Peripherals:** Voltage Regulation Modules (VRMs) for laptops and servers. * **Telecommunications:** Noise filtering and power management in networking gear. * **Battery Powered Devices:** Due to low DCR, it helps extend battery life by reducing heat loss. --- ### 5. Performance Characteristics * **Magnetic Shielding:** The closed magnetic path significantly reduces EMI, making it suitable for boards where components are packed tightly together. * **Saturation:** The inductor maintains its inductance value relatively well up to its saturation point, preventing sudden spikes in circuit current.