## Overview of CTX25-2-R The **CTX25-2-R** is a high-performance, surface-mount (SMD) toroidal power inductor manufactured by **Eaton (formerly Cooper Bussmann/Coiltronics)**. It belongs to the **OCTA-PAC®** series, known for its versatility in power conversion applications. --- ### 1. Technical Specifications The "25" in the part number refers to the approximate energy storage capability, while the "-2" indicates the specific winding configuration. | Parameter | Value / Specification | | :--- | :--- | | **Inductance (Parallel)** | 24.3 µH | | **Inductance (Series)** | 97.2 µH | | **Current Rating (Irms)** | ~1.65 A (Parallel) | | **DC Resistance (DCR)** | ~0.096 Ω (Parallel) | | **Operating Temperature** | -40°C to +125°C | | **Package Type** | Surface Mount (SMD) | | **Core Material** | Iron Powder (Toroidal) | --- ### 2. Key Features * **Dual Winding Construction:** It consists of two identical windings that can be connected in **series** or **parallel**. This allows the designer to double the inductance or double the current capacity depending on the circuit needs. * **Toroidal Geometry:** The doughnut-shaped core naturally contains the magnetic flux, resulting in **low Electromagnetic Interference (EMI)**. * **High Efficiency:** Iron powder cores offer good saturation characteristics, making them stable under high-current spikes. * **RoHS Compliant:** The "-R" suffix indicates that the part is lead-free and meets RoHS environmental standards. --- ### 3. Common Applications The CTX25-2-R is commonly used in power management circuits where space is at a premium and high efficiency is required: * **DC-DC Converters:** Buck, Boost, and Forward converters. * **Output Filter Chokes:** Used to smooth out ripple current in switching power supplies. * **Transformer Applications:** Can be used as a 1:1 isolation transformer or a coupled inductor in SEPIC topologies. * **Computer & Industrial Gear:** Found in VRMs (Voltage Regulator Modules) and industrial controllers. --- ### 4. Connection Diagram Because it has two windings, the PCB layout determines its behavior: ```text Parallel Connection: Series Connection: (Higher Current) (Higher Inductance) 1 o---+---o 4 1 o-------o 4 | | (bridge 2 to 3) 2 o---+---o 3 2 o---' o 3 ``` ---