## Technical Overview of 440LD68-R The **440LD68-R** is a specific type of ceramic disc capacitor designed for high-voltage applications. It belongs to the **Cera-Mite 440L Series**, manufactured by Vishay. These components are primarily used for electromagnetic interference (EMI) suppression and are safety-certified for across-the-line applications. --- ### 1. Key Technical Specifications The following table outlines the primary electrical characteristics of the 440LD68-R: | Parameter | Value / Specification | | :--- | :--- | | **Capacitance** | 6800 pF (0.0068 µF) | | **Capacitance Tolerance** | ±20% | | **Voltage Rating (AC)** | 440 VAC (X1), 300 VAC (Y1) | | **Dielectric Material** | Ceramic (Class 2) | | **Temperature Coefficient** | Y5U (Typical) | | **Mounting Type** | Through-Hole (Radial Leads) | | **Safety Class** | X1 / Y1 Rated | --- ### 2. Safety Classifications (X and Y Ratings) This part is specifically engineered to meet international safety standards (UL, CSA, VDE). * **X1 Rating:** Suitable for "Across-the-Line" use. If the capacitor fails, it is designed not to cause a fire, though it may cause a fuse to blow. * **Y1 Rating:** Suitable for "Line-to-Ground" use. This is the most stringent safety rating because a failure here could lead to a fatal electric shock. Y1 capacitors are designed to fail "open" to prevent the chassis from becoming energized. --- ### 3. Physical Construction The 440LD68-R consists of several layers to ensure durability and insulation: 1. **Ceramic Disc:** The core dielectric material that stores the charge. 2. **Silver Electrodes:** Applied to both sides of the disc for conductivity. 3. **Radial Leads:** Tinned copper wires for soldering onto PCBs. 4. **Encapsulation:** Coated with flame-retardant epoxy resin (UL 94 V-0 rated) to protect against moisture and mechanical stress. --- ### 4. Common Applications Due to its high-voltage safety rating, the 440LD68-R is found in: * **Power Supplies:** Filtering input noise in Switch Mode Power Supplies (SMPS). * **Home Appliances:** Used in washing machines, refrigerators, and ovens to prevent electrical noise from entering the grid. * **Industrial Equipment:** Protecting sensitive circuits from voltage surges. * **Modems and Chargers:** Bridging the primary (high voltage) and secondary (low voltage) sides of a circuit. --- ### 5. Part Number Breakdown While manufacturer codes vary slightly, the 440L series generally follows this logic: * **440L:** Series identifier (High voltage/Safety rated). * **D68:** Represents the capacitance value (68 x 10^2 pF = 6800 pF). * **-R:** Often signifies RoHS compliance (Restriction of Hazardous Substances).