The **47LPQ-42B-R** is a specific part number belonging to a series of high-performance **Common Mode Chokes** (Filters), typically manufactured by companies like **Coilcraft** or similar magnetic component specialists. These components are primarily used to suppress electromagnetic interference (EMI) in power and signal lines. --- ### 1. Technical Specifications Below is a breakdown of the typical technical characteristics for this component: | Parameter | Description | | :--- | :--- | | **Component Type** | Common Mode Choke | | **Series** | 47LPQ (Low Profile / High Performance) | | **Inductance** | Typically around 42 mH (varies by specific binning) | | **Rated Current** | Designed for low to medium current applications | | **Isolation Voltage** | Usually rated for 1000Vrms to 1500Vrms | | **Mounting Type** | Through-hole (typically 4-pin configuration) | | **Core Material** | High-permeability Ferrite | --- ### 2. Key Features * **Low Profile:** The "LPQ" designation often refers to a "Low Profile" design, making it suitable for compact electronic assemblies where vertical space is limited. * **High Impedance:** Designed to provide high impedance over a wide frequency range to effectively block high-frequency noise while allowing the desired signal/power to pass. * **RoHS Compliant:** The **-R** suffix typically indicates that the part is compliant with **RoHS** (Restriction of Hazardous Substances) standards (Lead-free). --- ### 3. Applications The 47LPQ-42B-R is commonly found in the following environments: 1. **Switch Mode Power Supplies (SMPS):** Used on the AC input side to prevent noise from the power supply from feeding back into the utility grid. 2. **Data Line Filtering:** Protecting sensitive communication lines from external EMI/RFI. 3. **Industrial Electronics:** Ensuring electromagnetic compatibility (EMC) in factory automation equipment. 4. **LED Drivers:** Reducing flickering or interference caused by high-frequency switching. --- ### 4. How it Works A common mode choke works by presenting a high impedance to signals that are common to both lines (noise), while presenting low impedance to differential signals (the actual power or data). ```mathematics Z = 2 * π * f * L ``` *Where **Z** is impedance, **f** is frequency, and **L** is inductance. As noise frequency increases, the choke's opposition to that noise also increases.*