The **SDR10A** is a specialized high-performance power inductor, typically categorized as a **Surface Mount Device (SMD) Shielded Power Inductor**. It is widely used in power management circuits, such as DC-DC converters, due to its ability to handle high currents while maintaining a compact footprint. --- ### 1. Key Technical Specifications The "10A" in the series name often refers to the physical dimensions (approximately 10mm x 10mm) rather than a 10 Ampere rating (though saturation currents can reach that level depending on the specific inductance value). | Feature | Description | | :--- | :--- | | **Inductance Range** | Typically 1.0 µH to 1000 µH | | **Construction** | Ferrite drum core with a magnetic shield | | **Mounting Type** | Surface Mount (SMD/SMT) | | **Operating Temp** | -40°C to +125°C (includes self-heating) | | **Shielding** | Magnetically shielded to minimize EMI | --- ### 2. Physical Structure and Materials The SDR10A inductor consists of three primary electronic components: 1. **Ferrite Core:** The "Drum" or "Spool" core made of ferrite material which provides the magnetic permeability necessary to store energy. 2. **Copper Winding:** Enameled copper wire wound around the core. The thickness of this wire determines the **DCR** (Direct Current Resistance) and the current handling capability. 3. **Magnetic Shield:** A ferrite ring or epoxy-resin coating that surrounds the winding. This prevents the magnetic field from interfering with nearby sensitive components on the PCB. --- ### 3. Electrical Characteristics When selecting an SDR10A part for a circuit, engineers focus on these three parameters: * **DCR (DC Resistance):** The internal resistance of the copper wire. A lower DCR is preferred to reduce power loss and heat generation. * **Isat (Saturation Current):** The current level at which the inductance drops by a specific percentage (usually 10-30%). Exceeding this causes the inductor to lose its effectiveness. * **Irms (RMS Current):** The continuous current that causes the temperature of the part to rise by a specific amount (usually 40°C). --- ### 4. Common Applications Due to its shielded nature and high energy storage, the SDR10A is commonly found in: * **Switching Mode Power Supplies (SMPS)** * **DC-DC Converters** for laptops and tablets. * **LED Driver Circuits.** * **Input/Output Filters** for noise suppression. --- ### 5. Example Part Numbering (Bourns Style) `SDR1006 - 100 M L` * **SDR:** Series Name (Standard Shielded Inductor) * **1006:** Dimensions (10mm width, 6mm height) * **100:** Inductance Value (10 x 10^0 = 10 µH) * **M:** Tolerance (e.g., ±20%)