## Overview: CTX1-2A-R Inductor The **CTX1-2A-R** is a specific surface-mount (SMT) dual-winding inductor manufactured by **Eaton (formerly Cooper Bussmann/Coiltronics)**. It belongs to the **OCTA-PAC®** series, known for its versatility in power conversion circuits. --- ### 1. Key Technical Specifications The following table outlines the electrical and physical characteristics of the CTX1-2A-R: | Parameter | Specification | | :--- | :--- | | **Inductance (Parallel)** | 1.15 µH | | **Inductance (Series)** | 4.6 µH | | **Current Rating (RMS)** | 6.4 A (Parallel) / 3.2 A (Series) | | **DC Resistance (DCR)** | 0.0104 Ω (Parallel) / 0.0416 Ω (Series) | | **Tolerance** | ±20% | | **Core Material** | Iron Powder (High saturation) | | **Operating Temperature** | -40°C to +125°C | | **Mounting Type** | Surface Mount (SMD) | --- ### 2. Core Functional Features #### Dual Winding Design The most significant feature of this part is that it contains **two separate windings** on a single core. This allows the component to be configured in three different ways depending on the PCB layout: 1. **Parallel Connection:** Increases current capacity and lowers total inductance. 2. **Series Connection:** Increases total inductance. 3. **1:1 Transformer:** Can be used for isolation or SEPIC (Single-Ended Primary-Inductor Converter) topologies. #### High Power Density The OCTA-PAC® design utilizes an iron powder toroid core which provides: * **Low EMI:** The toroidal shape naturally contains the magnetic flux. * **Soft Saturation:** Unlike ferrite cores that lose inductance sharply, iron powder cores saturate gradually, making them safer for high-current spikes. --- ### 3. Common Applications The CTX1-2A-R is typically found in the following electronic circuits: * **DC-DC Converters:** Used as a storage inductor in Buck, Boost, or Buck-Boost regulators. * **SEPIC Converters:** Leveraging the dual windings to maintain a steady output voltage regardless of whether the input is higher or lower. * **Filters:** Used in EMI/RFI filtering for power supplies. * **Battery Powered Systems:** Due to its small SMT footprint and high efficiency. --- ### 4. Schematic Representation When designing with this part, the pinout is crucial. In a standard SMT footprint: * **Winding 1:** Pins 1 and 4 * **Winding 2:** Pins 2 and 3 ```text (Start) 1 o---( Winding 1 )---o 4 (End) (Start) 2 o---( Winding 2 )---o 3 (End) ```