## DRQ73-221-R: Technical Overview The **DRQ73-221-R** is a high-performance, dual-winding shielded drum core inductor manufactured by Eaton (formerly Coiltronics). It belongs to the **DRQ series**, which is specifically designed for applications requiring two coupled inductors in a single surface-mount package. --- ### 1. Key Technical Specifications | Parameter | Value | | :--- | :--- | | **Inductance (Nominal)** | 220 µH | | **Inductance Tolerance** | ±20% | | **DC Resistance (DCR) Max** | 1.15 Ω (per winding) | | **Isat (Saturation Current)** | ~0.46 A (parallel) | | **Irms (Rated Current)** | ~0.49 A (parallel) | | **Operating Temperature** | -40°C to +125°C | | **Mounting Type** | Surface Mount (SMD) | | **Dimensions** | 7.6mm x 7.6mm x 3.55mm | --- ### 2. Physical Construction & Parts * **Core Material:** Ferrite drum core. Ferrite is used for its high magnetic permeability and low electrical conductivity, which reduces eddy current losses. * **Shielding:** The component is magnetically shielded. This minimizes Electro-Magnetic Interference (EMI) with surrounding components, making it ideal for high-density boards. * **Dual Windings:** It consists of two identical windings. This is the "Dual" aspect, which allows the component to be used in various configurations (Series, Parallel, or as a Transformer). * **Terminations:** Matte tin over copper leads, ensuring high solderability and RoHS compliance. --- ### 3. Functional Applications Because it features two separate windings, the **DRQ73-221-R** is versatile: 1. **SEPIC Converters:** The dual winding is essential for Single-Ended Primary-Inductor Converters where two inductors are needed to regulate a voltage that can be higher or lower than the input. 2. **Common Mode Choke:** It can be used to filter out noise that is common to two power lines. 3. **1:1 Transformers:** It can act as a basic isolation transformer or for voltage doubling/halving applications. 4. **Series/Parallel Inductor:** * **Parallel:** Increases current handling capability. * **Series:** Increases total inductance (up to 880 µH if coupled correctly). --- ### 4. Part Number Breakdown | Segment | Meaning | | :--- | :--- | | **DRQ** | Dual Winding Shielded Drum Core Series | | **73** | Size Code (Approx. 7.6mm x 7.6mm) | | **221** | Inductance Code (22 followed by 1 zero = 220 µH) | | **-R** | RoHS Compliant | ---