The **SDQ25-2R2-R** is a high-performance, surface-mount (SMD) **dual-winding shielded inductor** manufactured by Eaton (formerly Bussmann/Coiltronics). These components are versatile because they contain two identical coils in a single package. --- ### 1. Technical Specifications Below are the primary electrical and physical characteristics of the SDQ25-2R2-R: | Property | Value | | :--- | :--- | | **Inductance** | 2.2 µH (per winding) | | **Tolerance** | ±20% | | **Rated Current ($I_{rms}$)** | 3.39 Amperes | | **Saturation Current ($I_{sat}$)** | 5.23 Amperes | | **DC Resistance (DCR)** | 0.0267 Ω (Max) | | **Operating Temperature** | -40°C to +125°C | | **Shielding** | Magnetically Shielded | | **Dimensions** | 5.2mm x 5.2mm x 2.5mm | --- ### 2. Key Features * **Dual Winding Construction:** It consists of two separate coils wound on the same core. These can be connected in series, in parallel, or used as a 1:1 transformer. * **Magnetic Shielding:** The component is shielded to minimize Electromagnetic Interference (EMI), making it suitable for high-density boards near sensitive components. * **High Power Density:** Provides high current handling capability relative to its small 5x5mm footprint. * **Versatility:** The "coupled" nature of the inductor allows it to function in various circuit topologies that a standard single inductor cannot. --- ### 3. Common Applications The SDQ25 series is specifically designed for DC-DC conversion and signal filtering: 1. **SEPIC Converters:** Used as the coupled inductor in Single-Ended Primary-Inductor Converters to provide stable output voltage regardless of whether the input is higher or lower than the output. 2. **Flyback Transformers:** Can act as a miniature 1:1 transformer for isolated power supplies. 3. **Common Mode Choke:** When wired correctly, it can filter out common-mode noise in power lines. 4. **Parallel/Series Inductor:** * **Parallel:** Doubles the current capacity (Inductance remains 2.2 µH). * **Series:** Increases the inductance to 8.8 µH (Inductance is $L_{total} = L_1 + L_2 + 2M$). --- ### 4. Part Number Breakdown * **SDQ:** Series name (Shielded Dual Winding). * **25:** Size code (approx. 2.5mm height). * **2R2:** Inductance value (2.2 µH; 'R' acts as the decimal point). * **R:** RoHS compliant. ---