The **CSN084F331M** is a high-performance **Common Mode Choke (Filter)**, typically used in surface-mount (SMD) applications for noise suppression in high-speed data lines. --- ## 1. Technical Specifications The part number breakdown usually refers to the size, material, and impedance value. | Parameter | Specification (Typical) | | :--- | :--- | | **Component Type** | Common Mode Choke | | **Case Size** | 0804 (approx. 2.0 x 1.2 mm) | | **Impedance** | 330 $\Omega$ (at 100MHz) | | **Tolerance** | ±20% (indicated by 'M') | | **Rated Current** | ~200mA to 400mA (model dependent) | | **DC Resistance (DCR)** | < 0.5 $\Omega$ | | **Operating Temperature** | -40°C to +125°C | --- ## 2. Key Features * **Noise Suppression:** Designed to eliminate electromagnetic interference (EMI) while allowing signals to pass through. * **Differential Mode Integrity:** It maintains the integrity of high-speed differential signals (like USB or HDMI) while filtering common-mode noise. * **Compact Footprint:** The 0804 size is ideal for high-density PCB layouts in portable electronics. --- ## 3. How It Works The CSN084F331M consists of two coils wound around a single ferrite core. * **Common Mode:** Noise traveling in the same direction on both lines creates a high-impedance magnetic field in the core, which blocks the noise. * **Differential Mode:** Signal currents traveling in opposite directions cancel out the magnetic field, allowing the signal to pass with minimal distortion. --- ## 4. Typical Applications This component is widely used in interfaces where data integrity is critical: 1. **USB 2.0 / 3.0 Lines:** Filtering noise in computer peripherals. 2. **HDMI / DisplayPort:** Maintaining high-definition video signal purity. 3. **MIPI / D-PHY:** Used in mobile phone camera and display modules. 4. **CAN-Bus:** Automotive communication lines. --- ## 5. Equivalent Replacement Guide If you are looking for alternatives, ensure they match the **0804 footprint** and the **330 $\Omega$ impedance**. * **Murata:** DLM11SN series * **TDK:** TCM series * **Taiyo Yuden:** MC series