The **CTX5-2P-R** is a high-performance, dual-winding toroidal power inductor manufactured by Eaton (formerly Cooper Bussmann/Coiltronics). It is part of the **OCTA-PAC®** series, known for its versatility in DC-DC conversion and filtering applications. --- ### 1. Key Technical Specifications The "2P" in the part number indicates it is a size 2 package, and the "R" denotes RoHS compliance. | Feature | Specification | | :--- | :--- | | **Inductance (Parallel)** | 4.88 µH | | **Inductance (Series)** | 19.5 µH | | **Current Rating (Parallel)** | 4.4 Amps | | **Current Rating (Series)** | 2.2 Amps | | **DCR (Direct Current Resistance)** | ~0.024 Ω (Parallel) | | **Operating Temperature** | -40°C to +125°C | | **Mounting Type** | Surface Mount (SMD) | --- ### 2. Functional Design: Dual Winding The CTX5-2P-R features **two identical windings** on a single core. This provides the design engineer with three primary configuration options: 1. **Parallel Connection:** Connect the start/finish pins together to double the current capacity while keeping the base inductance. 2. **Series Connection:** Connect the windings in series to quadruple the inductance (due to mutual coupling) at half the current capacity. 3. **1:1 Transformer:** Use the two windings as a primary and secondary for isolated power supplies or SEPIC converters. --- ### 3. Construction and Materials * **Core Material:** Powered iron toroid. This shape is inherently "self-shielding," which significantly reduces Electromagnetic Interference (EMI) compared to open-bobbin inductors. * **Packaging:** High-temperature liquid crystal polymer (LCP) base, making it suitable for infrared and vapor phase reflow soldering. * **Shielding:** The toroidal geometry naturally minimizes external magnetic fields. --- ### 4. Common Applications Due to its dual-winding nature and compact SMD footprint, it is frequently used in: * **SEPIC Converters:** Single-Ended Primary-Inductor Converters. * **Buck/Boost Regulators:** For voltage stepping. * **Common Mode Chokes:** Used to filter noise on DC power lines. * **Isolation:** Providing basic galvanic isolation between two circuits. --- ### 5. Part Number Breakdown ```text CTX 5 - 2 P - R | | | | | | | | | +-- RoHS Compliant | | | +-------- Power / High Current | | +------------ Size (Physical dimensions) | +------------------ Inductance Code +----------------------- OCTA-PAC Series Prefix ```