The **CTX25-2A-R** is a high-performance, surface-mount (SMT) dual-winding inductor/transformer manufactured by Eaton (formerly Cooper Bussmann/Coiltronics) under the **OCTA-PAC®** series. ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Inductance** | 24.5 µH (Parallel) / 98 µH (Series) | | **Current Rating (Irms)** | 2.15 A (Parallel) | | **DCR (Direct Current Resistance)** | 0.054 Ω (Parallel) | | **Turns Ratio** | 1:1 | | **Mounting Type** | Surface Mount (SMD/SMT) | | **Operating Temperature** | -40°C to +125°C | | **Size / Dimension** | 11.43mm L x 11.43mm W x 5.97mm H | --- ### 2. Functional Characteristics The "CTX" series is unique because it features **two identical windings**. This design allows for high versatility depending on how the pins are connected to the PCB: * **Parallel Configuration:** Used to increase the current carrying capacity while maintaining lower inductance. * **Series Configuration:** Used to quadruple the inductance (as inductance is proportional to the square of the turns) while maintaining the current rating of a single winding. * **1:1 Transformer Mode:** Can be used as an isolation transformer or a common-mode choke. --- ### 3. Applications The CTX25-2A-R is commonly found in power management circuits due to its high power density and shielded construction: 1. **DC-DC Converters:** Acts as the main energy storage inductor in Buck, Boost, or SEPIC topologies. 2. **Input/Output Filters:** Used as a dual-line filter to reduce Electromagnetic Interference (EMI). 3. **Voltage Isolation:** Provides 500V isolation between windings for sensitive signal or power paths. 4. **Energy Storage:** Ideal for battery-powered handheld equipment where space is limited. --- ### 4. Part Number Breakdown * **CTX:** Series Name (Coiltronics Octa-Pac). * **25:** Nominal Inductance value code. * **2:** Size/Frame dimension (Size 2). * **A:** High-current/Performance version. * **R:** RoHS compliant (Lead-free). ---