The **LF2628NP-R104** is a specific model of a **Common Mode Choke Coil**, typically manufactured by companies like Sumida. It is designed for noise suppression in AC power lines and signal lines. --- ## 1. Technical Specifications The part number "R104" usually denotes the inductance value. In the Sumida naming convention, the last digits represent the inductance in microhenries ($\mu H$). | Parameter | Specification (Typical) | | :--- | :--- | | **Component Type** | Common Mode Choke / Line Filter | | **Inductance** | $100\text{ mH}$ (Minimum) | | **Rated Current** | $0.4\text{A} - 0.6\text{A}$ (Dependent on temperature rise) | | **DC Resistance (DCR)** | $\approx 2.4\text{ }\Omega$ (Maximum per winding) | | **Rated Voltage** | $250\text{ VAC}$ | | **Mounting Type** | Through-Hole (THT) | | **Core Material** | Ferrite | --- ## 2. Construction & Working Principle The LF2628NP series features a **double-coil construction** on a single ferrite core. ### Key Electronic Mechanisms: * **Common Mode Suppression:** It presents high impedance to common-mode noise (signals traveling in the same direction on both wires) while allowing differential-mode signals (the actual power/data) to pass with minimal attenuation. * **Closed Magnetic Circuit:** The NP (Non-Permeability/standard core) series uses a closed loop design to minimize magnetic flux leakage, reducing interference with nearby components. * **Sectioned Winding:** The coils are usually wound in sections to reduce parasitic capacitance, which improves high-frequency performance. --- ## 3. Applications This part is primarily used as a front-end filter to comply with Electromagnetic Compatibility (EMC) standards. 1. **Switching Mode Power Supplies (SMPS):** To prevent high-frequency switching noise from feeding back into the AC mains. 2. **LED Drivers:** Reducing flicker-related EMI. 3. **Home Appliances:** Filtering noise from motors or internal microcontrollers. 4. **Audio/Visual Equipment:** Ensuring a clean power signal to prevent "hum" or visual artifacts. --- ## 4. Equivalent Circuit The internal layout consists of two identical windings. In a schematic, it appears as: ```text Line In (1) o---( Coil 1 )---o Line Out (4) ( Core ) Neutral In (2) o---( Coil 2 )---o Neutral Out (3) ``` *Note: Pins 1-4 and 2-3 are magnetically coupled.*