The part number **MEX-F-13221-R** typically refers to a high-quality **Metallized Polypropylene Film Capacitor** (often categorized as an X2 suppression capacitor). These components are essential in power supply circuits for noise filtering and safety. --- ### 1. Key Technical Specifications Based on the standard nomenclature for the MEX-F series, here are the general technical parameters: | Parameter | Specification | | :--- | :--- | | **Capacitance** | Typically 0.001μF to 2.2μF (Specific to sub-code) | | **Voltage Rating** | 275V AC / 300V AC / 310V AC | | **Dielectric Material** | Metallized Polypropylene Film | | **Safety Class** | X2 (Across-the-line applications) | | **Tolerance** | ±10% (K) or ±20% (M) | | **Operating Temp** | -40°C to +105°C / +110°C | ### 2. Physical and Material Construction * **Encapsulation:** The internal element is housed in a flame-retardant plastic case (UL94V-0) and sealed with epoxy resin. * **Self-Healing Property:** If a dielectric breakdown occurs due to an overvoltage spike, the metallized layer evaporates around the point of failure, "healing" the capacitor and preventing a short circuit. * **Terminals:** Usually features tinned radial leads for Through-Hole Technology (THT) mounting on PCBs. ### 3. Applications and Usage The "X2" designation means this part is specifically designed to be connected across AC power lines. 1. **EMI/RFI Filtering:** Reduces electromagnetic interference and radio frequency interference generated by the device or coming from the power grid. 2. **Power Supplies:** Used in Switched-Mode Power Supplies (SMPS) as a "safety" capacitor. 3. **Antenna Coupling:** Used in circuits where safety is paramount to prevent electric shock if the capacitor fails. ### 4. Safety Standards Components like the MEX-F series are strictly regulated. They usually comply with: * **UL/cUL:** North American safety standards. * **VDE/ENEC:** European safety standards. * **CQC:** Chinese safety certification. --- ### Summary Checklist for Identification * **"MEX"**: Series name (Metallized Polypropylene). * **"X2"**: Safety rating for use across AC mains. * **"-R"**: Often denotes "RoHS Compliant" or a specific Lead Pitch/Taping style.