The **DRQ74-681-R** is a high-performance, dual-winding shielded inductor manufactured by Eaton (formerly Cooper Bussmann/Coiltronics). It is part of the DRQ series, known for its versatility in power electronics. --- ### 1. Technical Specifications The following table highlights the primary electrical and physical characteristics of the component: | Parameter | Specification | | :--- | :--- | | **Inductance** | 680 µH (nominal) | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | ~1.65 Ω (per winding) | | **RMS Current ($I_{rms}$)** | 0.44 A | | **Saturation Current ($I_{sat}$)** | 0.51 A | | **Configuration** | Dual Winding (4 terminals) | | **Shielding** | Magnetically Shielded | | **Operating Temperature** | -40°C to +125°C | --- ### 2. Key Features * **Dual Winding Design:** Consists of two identical coils wound on a single core. This allows the part to be used as an inductor, a transformer (1:1 ratio), or a common-mode choke. * **Magnetic Shielding:** The construction minimizes Electromagnetic Interference (EMI), making it suitable for high-density boards near sensitive components. * **High Efficiency:** Designed for low core losses and high power density. * **Surface Mount (SMT):** Packaged for automated assembly in a compact 7.6mm x 7.6mm footprint. --- ### 3. Common Applications Because of its dual-coil nature, the DRQ74-681-R is used in various circuit topologies: 1. **Buck/Boost Converters:** Used as a standard storage inductor. 2. **SEPIC Converters:** The two windings provide the necessary coupling for Single-Ended Primary-Inductor Converters. 3. **1:1 Transformers:** Ideal for isolation or providing a secondary voltage rail. 4. **Common Mode Filters:** Used in DC-DC converters to filter out noise on power lines. --- ### 4. Connection Options The component can be wired in three primary ways depending on the circuit requirements: * **Series Connection:** Increases total inductance (Inductance becomes $4 \times L$). * **Parallel Connection:** Increases current handling capability while maintaining the base inductance value (Inductance stays $L$, current capacity doubles). * **Isolated/Coupled:** Windings act independently as a 1:1 transformer.