### CTX5-4-R Electronic Component Overview The **CTX5-4-R** is a high-performance, surface-mount (SMT) power inductor/transformer belonging to the **OCTA-PAC®** series manufactured by Eaton (formerly Cooper Bussmann/Coiltronics). It is characterized by its **toroidal core geometry** and **dual-winding configuration**, which provides high efficiency and low electromagnetic interference (EMI). --- ### 1. Key Technical Specifications The "5-4-R" suffix defines the specific inductance and current rating within the product family. | Parameter | Specification | | :--- | :--- | | **Inductance (Parallel)** | 5.37 $\mu$H | | **Inductance (Series)** | 21.48 $\mu$H | | **Current Rating (Irms)** | 6.4 Amps (Parallel) | | **DCR (Direct Current Resistance)** | 0.0152 $\Omega$ (Parallel) | | **Configuration** | Dual Winding (1:1 Ratio) | | **Operating Temperature** | -40°C to +125°C | | **Mounting Type** | Surface Mount (SMD) | --- ### 2. Design and Construction The CTX5-4-R is engineered for versatility and durability in power electronic circuits: * **Toroidal Core:** The ring-shaped core (typically powdered iron or ferrite) ensures that the magnetic flux is contained within the core, significantly reducing EMI compared to traditional E-core inductors. * **Dual Windings:** It features two identical windings. This allows the user to connect them in **series** (to increase inductance) or **parallel** (to increase current capacity). * **Rugged Packaging:** The "-R" indicates RoHS compliance. The part is encapsulated in a base header that protects the fine copper wire and ensures stable SMT soldering. --- ### 3. Common Applications Due to its dual-winding nature, the CTX5-4-R is used in several distinct roles: 1. **DC-DC Converters:** Acts as an output filter inductor in Buck, Boost, and SEPIC topologies. 2. **Common Mode Choke:** When wired correctly, it can be used to filter out high-frequency noise in power lines. 3. **1:1 Transformers:** Can be used as an isolation transformer or a flyback transformer for low-power applications. 4. **Energy Storage:** Ideal for high-density power supplies in industrial and telecommunications equipment. --- ### 4. Wiring Configurations How you solder the pins determines the electrical behavior: | Connection Type | Effect | Use Case | | :--- | :--- | :--- | | **Parallel** | Lower Inductance, Higher Current | High-current buck regulators. | | **Series** | Higher Inductance, Lower Current | High-voltage ripple filtering. | | **Isolated** | Two separate circuits | Signal coupling or isolation. | ---