The **CTX210409-R** is a specific surface-mount power inductor manufactured by **Eaton (formerly Cooper Bussmann)**. It belongs to the **OCTA-PAC® Plus** series, which is known for its high power density and versatility in power conversion applications. --- ## 1. General Specifications The CTX210409-R is a dual-winding toroidal inductor. Because it has two separate windings, it can be configured in several ways: series, parallel, or as a 1:1 transformer. | Feature | Specification | | :--- | :--- | | **Manufacturer** | Eaton (Electronics Division) | | **Series** | OCTA-PAC® Plus (Size 1) | | **Inductance (Parallel)** | ~1.10 µH | | **Inductance (Series)** | ~4.40 µH | | **Current Rating (Isat)** | ~11.5 A to 23.0 A (Depending on config) | | **Mounting Type** | Surface Mount (SMD) | | **Core Material** | Powdered Iron (Lower cost, high saturation) | | **Operating Temperature** | -40°C to +125°C | --- ## 2. Key Characteristics ### High Power Density The toroidal (ring-shaped) design ensures that the magnetic flux is contained within the core. This minimizes **Electromagnetic Interference (EMI)** and allows for high energy storage in a small footprint. ### Dual Winding Versatility The part features four terminals. This allows the design engineer to use it in three primary modes: 1. **Parallel Mode:** Increases current capacity but lowers total inductance. 2. **Series Mode:** Increases total inductance but lowers the current rating. 3. **Transformer/Coupled Inductor Mode:** Used in SEPIC or Flyback converters where isolation or specific voltage ratios are needed. ### Robust Construction The "Plus" designation in the series indicates improved thermal performance and higher power handling compared to the standard OCTA-PAC line. It is designed to handle high-frequency switching up to 500 kHz or more. --- ## 3. Typical Applications This component is commonly found in industrial and consumer power electronics, including: * **DC-DC Converters:** Buck, Boost, and Forward converters. * **SEPIC Converters:** Utilizing the dual-winding as a coupled inductor. * **Voltage Regulator Modules (VRMs):** Found on server boards and high-performance computing. * **Battery Powered Systems:** Where high efficiency and small size are critical. --- ## 4. Connection Diagram The internal structure can be visualized as two identical coils: ```text Pin 1 ●-------) )-------● Pin 4 (Coil A) Pin 2 ●-------) )-------● Pin 3 (Coil B) ``` * **Parallel:** Connect 1 to 2 and 3 to 4. * **Series:** Connect 2 to 3; input at 1 and output at 4. ---