The **CMS1-5-R** is a high-performance, surface-mount common mode choke designed by Eaton (formerly Bussmann). It is part of the CMS series of inductors primarily used for EMI (Electromagnetic Interference) filtering and noise suppression in power electronics. --- ### 1. Technical Specifications The following table outlines the key electrical and physical characteristics of the CMS1-5-R: | Parameter | Specification | | :--- | :--- | | **Inductance (Typical)** | 165 µH | | **Rated Current ($I_{rms}$)** | 1.1 Amps | | **DC Resistance (DCR)** | 0.220 Ω (Max) | | **Operating Temperature** | -40°C to +125°C | | **Mounting Type** | Surface Mount (SMD) | | **Package/Case** | Vertical or Horizontal Toroidal | --- ### 2. Key Features and Construction * **Common Mode Suppression:** It is specifically designed to filter out high-frequency noise that is common to both signal lines, while allowing the desired differential signal to pass through. * **Toroidal Core Technology:** Uses a ferrite core in a toroidal (ring) shape. This geometry is highly efficient as it contains the magnetic flux within the core, reducing stray magnetic fields and interference with nearby components. * **RoHS Compliant:** The "-R" suffix indicates that the part is lead-free and compliant with RoHS standards. * **Compact Footprint:** Designed for automated assembly on PCBs where vertical space may be limited. --- ### 3. Application Areas The CMS1-5-R is commonly integrated into the following systems: 1. **Switch Mode Power Supplies (SMPS):** To filter out switching noise before it reaches the power grid or the load. 2. **DC-DC Converters:** Acts as an input/output filter to stabilize current. 3. **Data Lines:** Used in telecommunications to ensure signal integrity by removing common-mode hum or EMI. 4. **Industrial Electronics:** Protecting sensitive control circuits from environmental electrical noise. --- ### 4. Schematic Representation In a circuit diagram, the CMS1-5-R is represented as two coupled inductors sharing a single core: ```text Line In (+) ----( Coil 1 )---- Line Out (+) || (Core) Line In (-) ----( Coil 2 )---- Line Out (-) ``` ---