## Overview of CTX15-3A-R The **CTX15-3A-R** is a high-performance, surface-mount (SMT) power inductor belonging to the **OCTA-PAC®** series manufactured by Eaton (formerly Cooper Bussmann/Coiltronics). This specific component is unique because it features **dual windings**, allowing it to be configured in multiple ways depending on how the pins are connected on a PCB. --- ### 1. Technical Specifications | Parameter | Specification (Series Connection) | Specification (Parallel Connection) | | :--- | :--- | :--- | | **Inductance** | 59.94 µH | 14.99 µH | | **Rated Current ($I_{rms}$)** | 1.05 A | 2.10 A | | **Saturation Current ($I_{sat}$)** | 1.28 A | 2.56 A | | **DC Resistance (DCR)** | 0.380 Ω | 0.095 Ω | | **Operating Temp** | -40°C to +125°C | -40°C to +125°C | --- ### 2. Key Features and Construction * **Dual Winding Design:** It consists of two identical coils wound on a single toroidal core. This provides flexibility: * **Series:** Higher inductance, lower current. * **Parallel:** Lower inductance, higher current. * **1:1 Transformer:** Can be used as a coupled inductor or a basic isolation transformer. * **Toroidal Core:** Uses a powdered iron core material. The toroidal shape is excellent for self-shielding, which minimizes Electromagnetic Interference (EMI). * **Surface Mount Package:** Designed for automated pick-and-place assembly. * **Ruggedness:** The "R" suffix typically denotes RoHS compliance. --- ### 3. Applications Due to its versatile dual-winding nature, the CTX15-3A-R is commonly used in: 1. **DC-DC Converters:** Buck, boost, forward, and flyback topologies. 2. **SEPIC Converters:** The dual windings make it ideal for Single-Ended Primary-Inductor Converters. 3. **EMI Filtering:** Can be used as a common-mode choke to filter noise out of power lines. 4. **Energy Storage:** Acts as a storage element in switching power supplies. --- ### 4. Connection Diagram (Internal) To use this part correctly, you must reference the pinout to ensure the windings are in phase: ```text Winding 1: Pins 1 (Start) to 4 (End) Winding 2: Pins 2 (Start) to 3 (End) [ Parallel Connection ] Connect Pin 1 to 2 (+) Connect Pin 4 to 3 (-) [ Series Connection ] Connect Pin 4 to 2 (Jumper) Input at Pin 1, Output at Pin 3 ```