The **CSAB1250A-R15M** is a high-current, surface-mount (SMD) power inductor commonly used in DC-DC converters, voltage regulator modules (VRMs), and high-frequency power supplies. It is designed for high efficiency and high power density. --- ## 1. Technical Specifications The part number follows a specific nomenclature that defines its physical and electrical characteristics. | Parameter | Specification | Description | | :--- | :--- | :--- | | **Inductance** | 0.15 µH | The nominal inductance value (R15 = 0.15). | | **Tolerance** | ±20% | Labeled by "M" (Standard tolerance for power inductors). | | **Current Rating (Irms)** | ~40A - 50A | The continuous current the part can handle without overheating. | | **Saturation Current (Isat)** | ~70A - 90A | The current at which inductance drops by a specified percentage (usually 20-30%). | | **DC Resistance (DCR)** | ~0.5 mΩ - 0.7 mΩ | Extremely low resistance to minimize power loss. | | **Footprint (Size)** | 12.5 x 12.5 mm | The physical dimensions (Case size 1250). | --- ## 2. Key Internal Components The construction of this part is optimized for high-frequency performance: 1. **Composite Metal Core:** Instead of traditional ferrite, these inductors often use a **molded metal powder core**. This allows for a "soft saturation" characteristic, meaning the inductance doesn't drop off instantly when the current increases. 2. **Flat Wire Coil:** Often utilizes flat copper wire rather than round wire. This increases the surface area, reducing the **Skin Effect** at high frequencies and lowering DCR. 3. **Shielded Design:** The molded body acts as a magnetic shield, significantly reducing Electromagnetic Interference (EMI) to surrounding components. --- ## 3. Applications Due to its low inductance (0.15 µH) and high current capability, this component is typically found in: * **Graphics Cards (GPUs):** Used in the multi-phase power stages of high-end video cards. * **CPU Voltage Regulators:** Found on server and desktop motherboards. * **Point of Load (POL) Converters:** High-speed switching regulators that step down voltage near the load. * **Battery Management Systems:** High-efficiency power paths. --- ## 4. Part Number Breakdown * **CSAB:** Series identifier (Metal Alloy Molded Inductor). * **1250:** Physical dimensions (roughly 12mm x 12mm; height is ~5.0mm). * **A:** Design or revision code. * **R15:** Inductance value (0.15 microhenries). * **M:** Tolerance (±20%).