The **SDQ12-8R2-R** is a specific surface-mount (SMD) power inductor part number, typically manufactured by **Eaton (formerly Cooper Bussmann)**. It belongs to the SDQ series of dual-winding, shielded drum core inductors. Below is a detailed breakdown of its electronic specifications and characteristics. ### 1. Key Technical Specifications | Parameter | Value / Description | | :--- | :--- | | **Inductance** | 8.2 µH | | **Tolerance** | ±20% | | **Rated Current ($I_{sat}$)** | ~1.31 A (Saturation current) | | **DC Resistance (DCR)** | ~0.115 Ω (Max) | | **Configuration** | Dual Winding (Coupled Inductor) | | **Shielding** | Magnetically Shielded | | **Package Size** | SDQ12 (Approx. 5.2mm x 5.2mm x 1.2mm) | --- ### 2. Physical Structure and Design * **Dual Winding:** The "Dual" nature means it contains two identical coils wound on a single ferrite core. This allows the part to be used in various configurations depending on how the pins are connected. * **Low Profile:** The "12" in the part number indicates a height of approximately 1.2 mm, making it ideal for thin consumer electronics. * **Shielded Construction:** The ferrite drum core is surrounded by a magnetic shield, which minimizes Electromagnetic Interference (EMI) and prevents the magnetic field from affecting nearby components. --- ### 3. Application Use Cases Because it has two windings, the SDQ12-8R2-R is highly versatile: 1. **SEPIC Converters:** Used in Single-Ended Primary-Inductor Converters where two inductors are needed to allow the output voltage to be higher or lower than the input. 2. **1:1 Transformers:** Can be used as a flyback transformer for low-power isolated supplies. 3. **Series/Parallel Inductors:** * **Series:** Connecting the two coils in series increases the total inductance (to ~32.8 µH). * **Parallel:** Connecting them in parallel maintains 8.2 µH but increases the current carrying capacity. 4. **Common Mode Choke:** Used for filtering noise in power lines. --- ### 4. Part Number Decoder Understanding the nomenclature helps in identifying variants: | Segment | Meaning | | :--- | :--- | | **SDQ** | Series Name (Shielded Dual Winding) | | **12** | Size/Height Code (1.2mm height) | | **8R2** | Inductance Value (8.2 microhenries) | | **-R** | RoHS Compliant | ---